MBS as default shell

18 files changed, 3019 insertions, 24 deletions

diff --git a/.gitignore b/.gitignore
index b9cdadb..b3a6928 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,4 +2,6 @@ home/
 etc/
 .err-logs/
 kst/
-.enchat
\ No newline at end of file
+.enchat
+.shell_history
+.lua_history
\ No newline at end of file
diff --git a/.mbs/bin/clear.lua b/.mbs/bin/clear.lua
new file mode 100644
index 0000000..3a8e8d7
--- /dev/null
+++ b/.mbs/bin/clear.lua
@@ -0,0 +1,4 @@
+local _, y = term.getCursorPos()
+
+term.scroll(y - 1)
+term.setCursorPos(1, 1)
\ No newline at end of file
diff --git a/.mbs/bin/help.lua b/.mbs/bin/help.lua
new file mode 100644
index 0000000..f92630f
--- /dev/null
+++ b/.mbs/bin/help.lua
@@ -0,0 +1,19 @@
+local topic = ... or "intro"
+
+if topic == "index" then
+  print("Help topics availiable:")
+  textutils.pagedTabulate(help.topics())
+else
+  local file_name = help.lookup(topic)
+  if not file_name then error("No help available", 0) end
+
+  local file = fs.open(file_name, "r")
+  -- Shouldn't happen, but nice to handle anyway
+  if not file then error("No help available", 0) end
+
+  local contents = file.readAll()
+  file.close()
+
+  local _, height = term.getCursorPos()
+  textutils.pagedPrint(contents, height - 3)
+end
\ No newline at end of file
diff --git a/.mbs/bin/lua.lua b/.mbs/bin/lua.lua
new file mode 100644
index 0000000..eed7aa9
--- /dev/null
+++ b/.mbs/bin/lua.lua
@@ -0,0 +1,416 @@
+if select('#', ...) > 0 then
+  print("This is an interactive Lua prompt.")
+  print("To run a lua program, just type its name.")
+  return
+end
+
+local input_colour,  output_colour, text_colour,          keyword_colour, comment_colour, string_colour =
+      colours.green, colours.cyan,  term.getTextColour(), colours.yellow, colours.grey,   colours.red
+local number_colour,   extra_colour, object_colour =
+      colours.magenta, colours.grey, colours.lightGrey
+
+local keywords = {
+  ["and"] = keyword_colour, ["break"] = keyword_colour, ["do"] = keyword_colour,
+  ["else"] = keyword_colour, ["elseif"] = keyword_colour, ["end"] = keyword_colour,
+  ["false"] = object_colour, ["for"] = keyword_colour, ["function"] = keyword_colour,
+  ["if"] = keyword_colour, ["in"] = keyword_colour, ["local"] = keyword_colour,
+  ["nil"] = object_colour, ["not"] = keyword_colour, ["or"] = keyword_colour,
+  ["repeat"] = keyword_colour, ["return"] = keyword_colour, ["then"] = keyword_colour,
+  ["true"] = object_colour, ["until"] = keyword_colour, ["while"] = keyword_colour,
+}
+
+local tokens = {
+  { "^%s+", text_colour },
+
+  -- Identifiers and keywords
+  { "^[%a_][%w_]*", function(match) return keywords[match] or text_colour end },
+
+  -- TODO: Exponents + hex, partial strings and comments
+
+  { "^%-%-%[%[.-%]%]", comment_colour },
+  { "^%-%-.*",         comment_colour },
+
+  { [[^".-[^\]"]], string_colour }, -- Complete strings
+  { [[^"[^"]*"?]], string_colour }, -- Incomplete strings
+  { [[^'.-[^\]']], string_colour }, -- Complete strings
+  { [[^'[^"]*'?]], string_colour }, -- Incomplete strings
+  { "^%[%[.-%]%]", string_colour },
+
+  { "^0x[a-fA-F0-9]*", number_colour }, -- Hexadecimal
+
+  { "^%d+%.%d*e[-+]?%d*", number_colour }, -- 23.4e+2
+  { "^%d+%.%d*", number_colour },          -- 23.2
+  { "^%d+e[-+]?%d*", number_colour },      -- 23e+2
+  { "^%d+", number_colour },               -- 23
+
+  { "^%.%d*e[-+]?%d*", number_colour },    -- .23e+2
+  { "^%.%d*", number_colour },             -- .23
+
+  { "^[^%w_]", text_colour }, -- Consume some unknown input
+}
+
+--- A basic highlighting function:
+local function highlight(line, start)
+  local find, type = string.find, type
+  for i = 1, #tokens do
+    local token = tokens[i]
+    local pat_start, pat_finish = find(line, token[1], start)
+    if pat_finish then
+      if type(token[2]) == "function" then
+        return pat_finish, token[2](line:sub(pat_start, pat_finish))
+      else
+        return pat_finish, token[2]
+      end
+    end
+  end
+
+  return #line, text_colour
+end
+
+local function write_with(colour, text)
+  term.setTextColour(colour)
+  write(text)
+end
+
+local function pretty_sort(a, b)
+  local ta, tb = type(a), type(b)
+
+  if ta == "string" then return tb ~= "string" or a < b
+  elseif tb == "string" then return false
+  end
+
+  if ta == "number" then return tb ~= "number" or a < b end
+  return false
+end
+
+local debug_info = type(debug) == "table" and type(debug.getinfo) == "function" and debug.getinfo
+local debug_local = type(debug) == "table" and type(debug.getlocal) == "function" and debug.getlocal
+local function pretty_function(fn)
+  local info = debug_info and debug_info(fn, "Su")
+
+  -- Include function source position if available
+  local name
+  if info and info.short_src and info.linedefined and info.linedefined >= 1 then
+    name = "function<" .. info.short_src .. ":" .. info.linedefined .. ">"
+  else
+    name = tostring(fn)
+  end
+
+  -- Include arguments if a Lua function and if available. Lua will report "C"
+  -- functions as variadic.
+  if info and info.what == "Lua" and info.nparams and debug_local then
+    local args = {}
+    for i = 1, info.nparams do args[i] = debug_local(fn, i) or "?" end
+    if info.isvararg then args[#args + 1] = "..." end
+    name = name .. "(" .. table.concat(args, ", ") .. ")"
+  end
+
+  return name
+end
+
+local function pretty_size(obj, tracking, limit)
+  local obj_type = type(obj)
+  if obj_type == "string" then return #string.format("%q", obj):gsub("\\\n", "\\n")
+  elseif obj_type == "function" then return #pretty_function(obj)
+  elseif obj_type ~= "table" or tracking[obj] then return #tostring(obj) end
+
+  local count = 2
+  tracking[obj] = true
+  for k, v in pairs(obj) do
+    count = count + pretty_size(k, tracking, limit) + pretty_size(v, tracking, limit)
+    if count >= limit then break end
+  end
+  tracking[obj] = nil
+  return count
+end
+
+local function pretty_impl(obj, tracking, width, height, indent, tuple_length)
+  local obj_type = type(obj)
+  if obj_type == "string" then
+    local formatted = string.format("%q", obj):gsub("\\\n", "\\n")
+
+    -- Strings are limited to the size of the current buffer with a bit of padding
+    local limit = math.max(8, math.floor(width * height * 0.8))
+    if #formatted > limit then
+      write_with(string_colour, formatted:sub(1, limit - 3))
+      write_with(extra_colour, "...")
+    else
+      write_with(string_colour, formatted)
+    end
+    return
+  elseif obj_type == "number" then
+    return write_with(number_colour, tostring(obj))
+  elseif obj_type == "function" then
+    return write_with(object_colour, pretty_function(obj))
+  elseif obj_type ~= "table" or tracking[obj] then
+    return write_with(object_colour, tostring(obj))
+  elseif (getmetatable(obj) or {}).__tostring then
+    return write_with(text_colour, tostring(obj))
+  end
+
+  local open, close = "{", "}"
+  if tuple_length then open, close = "(", ")" end
+
+  if (tuple_length == nil or tuple_length == 0) and next(obj) == nil then
+    return write_with(text_colour, open .. close)
+  elseif width <= 7 then
+    write_with(text_colour, open) write_with(extra_colour, " ... ") write_with(text_colour, close)
+    return
+  end
+
+  local should_newline = false
+  local length = tuple_length or #obj
+
+  -- Compute the "size" of this object and how many children it has.
+  local size, children, keys, kn = 2, 0, {}, 0
+  for k, v in pairs(obj) do
+    if type(k) == "number" and k >= 1 and k <= length and k % 1 == 0 then
+      local vs = pretty_size(v, tracking, width)
+      size = size + vs + 2
+      children = children + 1
+    else
+      kn = kn + 1
+      keys[kn] = k
+
+      local vs, ks = pretty_size(v, tracking, width), pretty_size(k, tracking, width)
+      size = size + vs + ks + 2
+      children = children + 2
+    end
+
+    -- Some aribtrary scale factor to stop long lines filling too much of the
+    -- screen
+    if size >= width * 0.6 then should_newline = true end
+  end
+
+  -- If we want to have multiple lines, but don't fit in one then abort!
+  if should_newline and height <= 1 then
+    write_with(text_colour, open) write_with(extra_colour, " ... ") write_with(text_colour, close)
+    return
+  end
+
+  -- Make sure our keys are in some sort of sensible order
+  table.sort(keys, pretty_sort)
+
+  local next_newline, sub_indent, child_width, child_height
+  if should_newline then
+    next_newline, sub_indent = ",\n", indent .. " "
+
+    -- We split our height over multiple items. A future improvement could be to
+    -- give more "height" to complex elements (such as tables)
+    height = height - 2
+    child_width, child_height = width - 2, math.ceil(height / children)
+
+    -- If there's more children then we have space then
+    if children > height then children = height - 2 end
+  else
+    next_newline, sub_indent =  ", ", ""
+
+    -- Like multi-line elements, we share the width across multiple children
+    width = width - 2
+    child_width, child_height = math.ceil(width / children), 1
+  end
+
+  write_with(text_colour, open .. (should_newline and "\n" or " "))
+
+  tracking[obj] = true
+  local seen = {}
+  local first = true
+  for k = 1, length do
+    if not first then write_with(text_colour, next_newline) else first = false end
+    write_with(text_colour, sub_indent)
+
+    seen[k] = true
+    pretty_impl(obj[k], tracking, child_width, child_height, sub_indent)
+
+    children = children - 1
+    if children < 0 then
+      if not first then write_with(text_colour, next_newline) else first = false end
+      write_with(extra_colour, sub_indent .. "...")
+      break
+    end
+  end
+
+  for i = 1, kn do
+    local k, v = keys[i], obj[keys[i]]
+    if not seen[k] then
+      if not first then write_with(text_colour, next_newline) else first = false end
+      write_with(text_colour, sub_indent)
+
+      if type(k) == "string" and not keywords[k] and string.match( k, "^[%a_][%a%d_]*$" ) then
+        write_with(text_colour, k .. " = ")
+        pretty_impl(v, tracking, child_width, child_height, sub_indent)
+      else
+        write_with(text_colour, "[")
+        pretty_impl(k, tracking, child_width, child_height, sub_indent)
+        write_with(text_colour, "] = ")
+        pretty_impl(v, tracking, child_width, child_height, sub_indent)
+      end
+
+      children = children - 1
+      if children < 0 then
+        if not first then write_with(text_colour, next_newline) else first = false end
+        write_with(extra_colour, sub_indent .. "...")
+        break
+      end
+    end
+  end
+  tracking[obj] = nil
+
+  write_with(text_colour, (should_newline and "\n" .. indent or " ") .. (tuple_length and ")" or "}"))
+end
+
+local function pretty(t, n)
+  local width, height = term.getSize()
+  local fit_height = settings.get("mbs.lua.pretty_height", true)
+  if type(fit_height) == "number" then height = fit_height
+  elseif fit_height == false then height = 1/0 end
+  return pretty_impl(t, {}, width, height - 2, "", n)
+end
+
+local running = true
+local history = {}
+local counter = 1
+local output = {}
+
+local environment = setmetatable({
+  exit = setmetatable({}, {
+    __tostring = function() return "Call exit() to exit" end,
+    __call = function() running = false end,
+  }),
+
+  _noTail = function(...) return ... end,
+
+  out = output,
+}, { __index = _ENV })
+
+local autocomplete = nil
+if not settings or settings.get("lua.autocomplete") then
+  autocomplete = function(line)
+    local start = line:find("[a-zA-Z0-9_%.:]+$")
+    if start then
+      line = line:sub(start)
+    end
+    if #line > 0 then
+      return textutils.complete(line, environment)
+    end
+  end
+end
+
+local history_file = settings.get("mbs.lua.history_file", ".lua_history")
+if history_file and fs.exists(history_file) then
+  local handle = fs.open(history_file, "r")
+  if handle then
+    for line in handle.readLine do history[#history + 1] = line end
+    handle.close()
+  end
+end
+
+local function set_output(out, length)
+  environment._ = out
+  environment['_' .. counter] = out
+  output[counter] = out
+
+  term.setTextColour(output_colour)
+  write("out[" .. counter .. "]: ")
+  term.setTextColour(text_colour)
+
+  if type(out) == "table" then
+    print(pretty(out, length))
+  else
+    print(pretty(out))
+  end
+end
+
+--- Handle the result of the function
+local function handle(force_print, success, ...)
+  if success then
+    local len = select('#', ...)
+    if len == 0 then
+      if force_print then
+        set_output(nil)
+      end
+    elseif len == 1 then
+      set_output(...)
+    else
+      set_output({...}, len)
+    end
+  else
+    printError(...)
+  end
+end
+
+if type(package) == "table" and type(package.path) == "string" then
+  -- Attempt to determine the shell directory with leading and trailing slashes
+  local dir = shell.dir()
+  if dir:sub(1, 1) ~= "/" then dir = "/" .. dir end
+  if dir:sub(#dir, #dir) ~= "/" then dir = dir .. "/" end
+
+  -- Strip the default "current program" package path
+  local strip_path = "?;?.lua;?/init.lua;"
+  local path = package.path
+  if path:sub(1, #strip_path) == strip_path then path = path:sub(#strip_path + 1) end
+
+  -- And append the current directory to the package path
+  package.path = dir .. "?;" .. dir .. "?.lua;" .. dir .. "?/init.lua;" .. path
+end
+
+while running do
+  term.setTextColour(input_colour)
+  term.write("in [" .. counter .. "]: ")
+  term.setTextColour(text_colour)
+
+  local line
+  if readline and readline.read and settings.get("mbs.lua.highlight") then
+    line = readline.read {
+      history = history,
+      complete = autocomplete,
+      highlight = highlight,
+    }
+  else
+    line = read(nil, history, autocomplete)
+  end
+  if not line then break end
+
+  if line:find("%S") then
+    if line ~= history[#history] then
+      -- Add item to history
+      history[#history + 1] = line
+
+      -- Remove extra items from history
+      local max = tonumber(settings.get("mbs.lua.history_max", 1e4)) or 1e4
+      while #history > max do table.remove(history, 1) end
+
+      -- Write history file
+      local history_file = settings.get("mbs.lua.history_file", ".lua_history")
+      if history_file then
+        local handle = fs.open(history_file, "w")
+        if handle then
+          for i = 1, #history do handle.writeLine(history[i]) end
+          handle.close()
+        end
+      end
+    end
+
+    local force_print = true
+    local func, e = load("return " .. line, "=lua", "t", environment)
+    if not func then
+      func, e = load(line, "=lua", "t", environment)
+      force_print = false
+    else
+      local wrapped_func = load("return _noTail(" .. line .. ")", "=lua", "t", environment)
+      if wrapped_func then func = wrapped_func end
+    end
+
+    if func then
+      if settings.get("mbs.lua.traceback", true) then
+        handle(force_print, stack_trace.xpcall_with(func))
+      else
+        handle(force_print, pcall(func))
+      end
+    else
+      printError(e)
+    end
+
+    counter = counter + 1
+  end
+end
\ No newline at end of file
diff --git a/.mbs/bin/mbs.lua b/.mbs/bin/mbs.lua
new file mode 100644
index 0000000..67fada6
--- /dev/null
+++ b/.mbs/bin/mbs.lua
@@ -0,0 +1,260 @@
+local arg = table.pack(...)
+local root_dir = ".mbs"
+local rom_dir = "rom/.mbs"
+local install_dir = fs.exists(root_dir) and root_dir or rom_dir
+local repo_url = "https://raw.githubusercontent.com/SquidDev-CC/mbs/master/"
+
+--- Write a string with the given colour to the terminal
+local function write_coloured(colour, text)
+  local old = term.getTextColour()
+  term.setTextColour(colour)
+  io.write(text)
+  term.setTextColour(old)
+end
+
+--- Print usage for this program
+local commands = { "install", "modules", "module", "download" }
+local function print_usage()
+  local name = fs.getName(shell.getRunningProgram()):gsub("%.lua$", "")
+  write_coloured(colours.cyan, name .. " modules  ") io.write("Print the status of all modules\n")
+  write_coloured(colours.cyan, name .. " module   ") io.write("Print information about a given module\n")
+  write_coloured(colours.cyan, name .. " install  ") io.write("Download all modules and create a startup file\n")
+  write_coloured(colours.cyan, name .. " download ") io.write("Download all modules WITHOUT creating a startup file\n")
+end
+
+--- Attempt to load a module from the given path, returning the module or false
+-- and an error message.
+local function load_module(path)
+  if fs.isDir(path) then return false, "Invalid module (is directory)" end
+
+  local fn, err = loadfile(path, _ENV)
+  if not fn then return false, "Invalid module (" .. err .. ")" end
+
+  local ok, res = pcall(fn)
+  if not ok then return false, "Invalid module (" .. res .. ")" end
+
+  if type(res) ~= "table" or type(res.description) ~= "string" or type(res.enabled) ~= "function" then
+    return false, "Malformed module"
+  end
+
+  return res
+end
+
+--- Setup all modules
+local function setup_module(module)
+  for _, setting in ipairs(module.settings) do
+    if settings.get(setting.name) == nil then
+      settings.set(setting.name, setting.default)
+    end
+  end
+end
+
+--- Download a set of files
+local function download_files(files)
+  if #files == 0 then return end
+
+  local urls = {}
+  for _, file in ipairs(files) do
+    local url = repo_url .. file
+    http.request(url)
+    urls[url] = file
+  end
+
+  while true do
+    local event, url, arg1 = os.pullEvent()
+    if event == "http_success" and urls[url] then
+      local handle = fs.open(fs.combine(root_dir, urls[url]), "w")
+      handle.write(arg1.readAll())
+      handle.close()
+      arg1.close()
+
+      urls[url] = nil
+      if next(urls) == nil then return end
+    elseif event == "http_failure" and urls[url] then
+      error("Could not download " .. urls[url], 0)
+    end
+  end
+end
+
+--- read completion helper, completes text using the given options
+local function complete_multi(text, options, add_spaces)
+  local results = {}
+  for n = 1, #options do
+    local option = options[n]
+    if #option + (add_spaces and 1 or 0) > #text and option:sub(1, #text) == text then
+      local result = option:sub(#text + 1)
+      if add_spaces then
+        results[#results + 1] = result .. " "
+      else
+        results[#results + 1] = result
+      end
+    end
+  end
+  return results
+end
+
+--- Append an object to a list if it is not already contained within
+local function add_unique(list, x)
+  for i = 1, #list do if list[i] == x then return end end
+  list[#list + 1] = x
+end
+
+local function load_all_modules()
+  -- Load all modules and update them.
+  local module_dir = fs.combine(root_dir, "modules")
+  local modules = fs.isDir(module_dir) and fs.list(module_dir) or {}
+
+  -- Add the default modules if not already there.
+  for _, module in ipairs { "lua.lua", "pager.lua", "readline.lua", "shell.lua" } do
+    add_unique(modules, module)
+  end
+
+  local files = {}
+  for i = 1, #modules do files[i] = "modules/" .. modules[i] end
+  download_files(files)
+
+  -- Scan for dependencies in enabled modules, downloading them as well
+  local deps = {}
+  for i = 1, #files do
+    local module = load_module(fs.combine(root_dir, files[i]))
+    if module then
+      setup_module(module)
+      if module.enabled() then
+        for _, dep in ipairs(module.dependencies) do deps[#deps + 1] = dep end
+      end
+    end
+  end
+  download_files(deps)
+end
+
+if arg.n == 0 then
+  printError("Expected some command")
+  print_usage()
+  error()
+elseif arg[1] == "download" then
+  load_all_modules()
+elseif arg[1] == "install" then
+  load_all_modules()
+
+  -- Move the existing startup file. We have to read the whole thing,
+  -- as otherwise we'd end up copying inside ourselves.
+  if fs.exists("startup") and not fs.isDir("startup") then
+    write_coloured(colours.cyan, "Moving your existing startup file to startup/30_startup.lua.\n")
+
+    local handle = fs.open("startup", "r")
+    local contents = handle.readAll()
+    handle.close()
+    fs.delete("startup")
+
+    handle = fs.open("startup/30_startup.lua", "w")
+    handle.write(contents)
+    handle.close()
+  end
+
+  -- Also move the startup.lua file afterwards
+  if fs.exists("startup.lua") and not fs.isDir("startup.lua") then
+    write_coloured(colours.cyan, "Moving your existing startup.lua file to startup/31_startup.lua.\n")
+    fs.move("startup.lua", "startup/31_startup.lua")
+  end
+
+  if fs.exists("startup/99_mbs.lua") then
+    write_coloured(colours.cyan, "Deleting the old startup/99_mbs.lua file. We now run before other startup files.\n")
+    fs.delete("startup/99_mbs.lua")
+  end
+
+  -- We'll run at the first possible position to ensure
+  local handle = fs.open("startup/00_mbs.lua", "w")
+  handle.writeLine(("assert(loadfile(%q, _ENV))('startup')"):format(shell.getRunningProgram()))
+  handle.close()
+
+  write_coloured(colours.green, "Installed! ")
+  io.write("Please reboot to apply changes.\n")
+elseif arg[1] == "startup" then
+  -- Gather a list of all modules
+  local module_dir = fs.combine(install_dir, "modules")
+  local files = fs.isDir(module_dir) and fs.list(module_dir) or {}
+
+  -- Load those modules and determine which are enabled.
+  local enabled = {}
+  local module_names = {}
+  for _, file in ipairs(files) do
+    local module = load_module(fs.combine(module_dir, file))
+    if module then
+      setup_module(module)
+      module_names[#module_names + 1] = file:gsub("%.lua$", "")
+      if module.enabled() then enabled[#enabled + 1] = module end
+    end
+  end
+
+  shell.setCompletionFunction(shell.getRunningProgram(), function(_, index, text, previous)
+    if index == 1 then
+      return complete_multi(text, commands, true)
+    elseif index == 2 and previous[#previous] == "module" then
+      return complete_multi(text, module_names, false)
+    end
+  end)
+
+  -- Setup those modules
+  for _, module in ipairs(enabled) do
+    if type(module.setup) == "function" then module.setup(install_dir) end
+  end
+
+  -- And run the startup hook if needed
+  for _, module in ipairs(enabled) do
+    if type(module.startup) == "function" then module.startup(install_dir) end
+  end
+
+elseif arg[1] == "modules" then
+  local module_dir = fs.combine(install_dir, "modules")
+  local files = fs.isDir(module_dir) and fs.list(module_dir) or {}
+  local found_any = false
+
+  for _, file in ipairs(files) do
+    local res, err = load_module(fs.combine(module_dir, file))
+    write_coloured(colours.cyan, file:gsub("%.lua$", "") .. " ")
+    if res then
+      write(res.description)
+      if res.enabled() then
+        write_coloured(colours.green, " (enabled)")
+      else
+        write_coloured(colours.red, " (disabled)")
+      end
+      found_any = true
+    else
+      write_coloured(colours.red, err)
+    end
+
+    io.write("\n")
+  end
+
+  if not found_any then error("No modules found. Maybe try running the `install` command?", 0) end
+elseif arg[1] == "module" then
+  if not arg[2] then error("Expected module name", 0) end
+  local module, err = load_module(fs.combine(install_dir, fs.combine("modules", arg[2] .. ".lua")))
+  if not module then error(err, 0) end
+
+  io.write(module.description)
+  if module.enabled() then
+    write_coloured(colours.green, " (enabled)")
+  else
+    write_coloured(colours.red, " (disabled)")
+  end
+  io.write("\n\n")
+
+  for _, setting in ipairs(module.settings) do
+    local value = settings.get(setting.name)
+    write_coloured(colours.cyan, setting.name)
+    io.write(" " .. setting.description .. " (")
+    write_coloured(colours.yellow, textutils.serialise(value))
+    if value ~= setting.default then
+      io.write(", default is \n")
+      write_coloured(colours.yellow, textutils.serialise(setting.default))
+    end
+
+    io.write(")\n")
+  end
+else
+  printError("Unknown command")
+  print_usage()
+  error()
+end
diff --git a/.mbs/bin/shell.lua b/.mbs/bin/shell.lua
new file mode 100644
index 0000000..6dd7d9c
--- /dev/null
+++ b/.mbs/bin/shell.lua
@@ -0,0 +1,702 @@
+
+local multishell = multishell
+local parentShell = shell
+
+if multishell then
+  multishell.setTitle(multishell.getCurrent(), "shell")
+end
+
+local bExit = false
+local sDir = (parentShell and parentShell.dir()) or ""
+local sPath = (parentShell and parentShell.path()) or ".:/rom/programs"
+local tAliases = (parentShell and parentShell.aliases()) or {}
+local tCompletionInfo = (parentShell and parentShell.getCompletionInfo()) or {}
+local tProgramStack = {}
+local history = parentShell and type(parentShell.history) == "function" and parentShell.history()
+local fWrapper = nil
+
+local shell = {}
+local function createShellEnv(sDir)
+  local tEnv = {}
+  tEnv["shell"] = shell
+  tEnv["multishell"] = multishell
+
+  if fWrapper then
+    if read then tEnv.read = fWrapper(read) end
+    if readline and readline.read then tEnv.readline = { read = fWrapper(readline.read) } end
+  end
+
+  local package = {}
+  package.loaded = {
+    _G = _G,
+    bit32 = bit32,
+    coroutine = coroutine,
+    math = math,
+    package = package,
+    string = string,
+    table = table,
+  }
+  package.path = settings.get('mbs.shell.require_path') or
+    "?;?.lua;?/init.lua;/rom/modules/main/?;/rom/modules/main/?.lua;/rom/modules/main/?/init.lua"
+  if turtle then
+    package.path = package.path..";/rom/modules/turtle/?;/rom/modules/turtle/?.lua;/rom/modules/turtle/?/init.lua"
+  elseif command then
+    package.path = package.path..";/rom/modules/command/?;/rom/modules/command/?.lua;/rom/modules/command/?/init.lua"
+  end
+  package.config = "/\n;\n?\n!\n-"
+  package.preload = {}
+  package.loaders = {
+    function(name)
+      if package.preload[name] then
+        return package.preload[name]
+      else
+        return nil, "no field package.preload['" .. name .. "']"
+      end
+    end,
+    function(name)
+      local fname = string.gsub(name, "%.", "/")
+      local sError = ""
+      for pattern in string.gmatch(package.path, "[^;]+") do
+        local sPath = string.gsub(pattern, "%?", fname)
+        if sPath:sub(1,1) ~= "/" then
+          sPath = fs.combine(sDir, sPath)
+        end
+        if fs.exists(sPath) and not fs.isDir(sPath) then
+          local fnFile, sError = loadfile(sPath, tEnv)
+          if fnFile then
+            return fnFile, sPath
+          else
+            return nil, sError
+          end
+        else
+          if #sError > 0 then
+            sError = sError .. "\n  "
+          end
+          sError = sError .. "no file '" .. sPath .. "'"
+        end
+      end
+      return nil, sError
+    end
+  }
+
+  local sentinel = {}
+  local function require(name)
+    if type(name) ~= "string" then
+      error("bad argument #1 (expected string, got " .. type(name) .. ")", 2)
+    end
+    if package.loaded[name] == sentinel then
+      error("loop or previous error loading module '" .. name .. "'", 0)
+    end
+    if package.loaded[name] then
+      return package.loaded[name]
+    end
+
+    local sError = "module '" .. name .. "' not found:"
+    for _, searcher in ipairs(package.loaders) do
+      local loader = table.pack(searcher(name))
+      if loader[1] then
+        package.loaded[name] = sentinel
+        local result = loader[1](name, table.unpack(loader, 2, loader.n))
+        if result == nil then result = true end
+
+        package.loaded[name] = result
+        return result
+      else
+        sError = sError .. "\n  " .. loader[2]
+      end
+    end
+    error(sError, 2)
+  end
+
+  tEnv["package"] = package
+  tEnv["require"] = require
+
+  return tEnv
+end
+
+-- Colours
+local promptColour, textColour, bgColour
+if term.isColour() then
+  promptColour = colours.yellow
+  textColour = colours.white
+  bgColour = colours.black
+else
+  promptColour = colours.white
+  textColour = colours.white
+  bgColour = colours.black
+end
+
+local function run(_sCommand, ...)
+  local sPath = shell.resolveProgram(_sCommand)
+  if sPath ~= nil then
+    tProgramStack[#tProgramStack + 1] = sPath
+    if multishell then
+      local sTitle = fs.getName(sPath)
+      if sTitle:sub(-4) == ".lua" then
+        sTitle = sTitle:sub(1,-5)
+      end
+      multishell.setTitle(multishell.getCurrent(), sTitle)
+    end
+    local sDir = fs.getDir(sPath)
+    local tEnv = setmetatable(createShellEnv(sDir), { __index = _G })
+
+    if settings.get("mbs.shell.strict_globals", false)  then
+      -- load (in bios.lua) will attempt to set _ENV on our environment, which
+      -- throws an error with this protection enabled. Thus we set it here first.
+      tEnv._ENV = tEnv
+      getmetatable(tEnv).__newindex = function(_, name)
+        error("Attempt to create global " .. tostring(name) .. "\n If this is intended then you probably want to use _G." .. tostring(name), 2)
+      end
+    end
+
+    local ok
+    local fnFile, err = loadfile(sPath, tEnv)
+    if fnFile then
+      if settings.get("mbs.shell.traceback", true) then
+        local tArgs = table.pack(...)
+        ok, err = stack_trace.xpcall_with(function() return fnFile(table.unpack(tArgs, 1, tArgs.n)) end)
+      else
+        ok, err = pcall(fnFile, ...)
+      end
+
+      if not ok then
+        ok = false
+        if err and err ~= "" then printError(err) end
+      end
+    else
+      ok = false
+      if err and err ~= "" then printError(err) end
+    end
+
+    tProgramStack[#tProgramStack] = nil
+    if multishell then
+      if #tProgramStack > 0 then
+        local sTitle = fs.getName(tProgramStack[#tProgramStack])
+        if sTitle:sub(-4) == ".lua" then
+          sTitle = sTitle:sub(1,-5)
+        end
+        multishell.setTitle(multishell.getCurrent(), sTitle)
+      else
+        multishell.setTitle(multishell.getCurrent(), "shell")
+      end
+    end
+    return ok
+  else
+    printError("No such program")
+    return false
+  end
+end
+
+local function tokenise(...)
+  local sLine = table.concat({ ... }, " ")
+  local tWords = {}
+  local bQuoted = false
+  for match in string.gmatch(sLine .. "\"", "(.-)\"") do
+    if bQuoted then
+      table.insert(tWords, match)
+    else
+      for m in string.gmatch(match, "[^ \t]+") do
+        table.insert(tWords, m)
+      end
+    end
+    bQuoted = not bQuoted
+  end
+  return tWords
+end
+
+-- Install shell API
+function shell.run(...)
+  local tWords = tokenise(...)
+  local sCommand = tWords[1]
+  if sCommand then
+    return run(sCommand, table.unpack(tWords, 2))
+  end
+  return false
+end
+
+function shell.exit()
+  bExit = true
+end
+
+function shell.dir()
+  return sDir
+end
+
+function shell.setDir(_sDir)
+  if type(_sDir) ~= "string" then
+    error("bad argument #1 (expected string, got " .. type(_sDir) .. ")", 2)
+  end
+  if not fs.isDir(_sDir) then
+    error("Not a directory", 2)
+  end
+  sDir = _sDir
+end
+
+function shell.path()
+  return sPath
+end
+
+function shell.setPath(_sPath)
+  if type(_sPath) ~= "string" then
+    error("bad argument #1 (expected string, got " .. type(_sPath) .. ")", 2)
+  end
+  sPath = _sPath
+end
+
+function shell.resolve(_sPath)
+  if type(_sPath) ~= "string" then
+    error("bad argument #1 (expected string, got " .. type(_sPath) .. ")", 2)
+  end
+  local sStartChar = string.sub(_sPath, 1, 1)
+  if sStartChar == "/" or sStartChar == "\\" then
+    return fs.combine("", _sPath)
+  else
+    return fs.combine(sDir, _sPath)
+  end
+end
+
+local function pathWithExtension(_sPath, _sExt)
+  local nLen = #sPath
+  local sEndChar = string.sub(_sPath, nLen, nLen)
+  -- Remove any trailing slashes so we can add an extension to the path safely
+  if sEndChar == "/" or sEndChar == "\\" then
+    _sPath = string.sub(_sPath, 1, nLen - 1)
+  end
+  return _sPath .. "." .. _sExt
+end
+
+function shell.resolveProgram(_sCommand)
+  if type(_sCommand) ~= "string" then
+    error("bad argument #1 (expected string, got " .. type(_sCommand) .. ")", 2)
+  end
+  -- Substitute aliases firsts
+  if tAliases[_sCommand] ~= nil then
+    _sCommand = tAliases[_sCommand]
+  end
+
+  -- If the path is a global path, use it directly
+  local sStartChar = string.sub(_sCommand, 1, 1)
+  if _sCommand:find("/") or _sCommand:find("\\") then
+    local sPath = shell.resolve(_sCommand)
+    if fs.exists(sPath) and not fs.isDir(sPath) then
+      return sPath
+    else
+      local sPathLua = pathWithExtension(sPath, "lua")
+      if fs.exists(sPathLua) and not fs.isDir(sPathLua) then
+        return sPathLua
+      end
+    end
+    return nil
+  end
+
+  -- Otherwise, look on the path variable
+  for sPath in string.gmatch(sPath, "[^:]+") do
+    sPath = fs.combine(shell.resolve(sPath), _sCommand)
+    if fs.exists(sPath) and not fs.isDir(sPath) then
+      return sPath
+    else
+      local sPathLua = pathWithExtension(sPath, "lua")
+      if fs.exists(sPathLua) and not fs.isDir(sPathLua) then
+        return sPathLua
+      end
+    end
+  end
+
+  -- Not found
+  return nil
+end
+
+function shell.programs(_bIncludeHidden)
+  local tItems = {}
+
+  -- Add programs from the path
+  for sPath in string.gmatch(sPath, "[^:]+") do
+    sPath = shell.resolve(sPath)
+    if fs.isDir(sPath) then
+      local tList = fs.list(sPath)
+      for n=1,#tList do
+        local sFile = tList[n]
+        if not fs.isDir(fs.combine(sPath, sFile)) and
+        (_bIncludeHidden or string.sub(sFile, 1, 1) ~= ".") then
+          if #sFile > 4 and sFile:sub(-4) == ".lua" then
+            sFile = sFile:sub(1,-5)
+          end
+          tItems[sFile] = true
+        end
+      end
+    end
+  end
+
+  -- Sort and return
+  local tItemList = {}
+  for sItem in pairs(tItems) do
+    table.insert(tItemList, sItem)
+  end
+  table.sort(tItemList)
+  return tItemList
+end
+
+local function completeProgram(sLine)
+  if #sLine > 0 and (sLine:find("/") or sLine:find("\\")) then
+    -- Add programs from the root
+    return fs.complete(sLine, sDir, true, false)
+
+  else
+    local tResults = {}
+    local tSeen = {}
+
+    -- Add aliases
+    for sAlias in pairs(tAliases) do
+      if #sAlias > #sLine and string.sub(sAlias, 1, #sLine) == sLine then
+        local sResult = string.sub(sAlias, #sLine + 1)
+        if not tSeen[sResult] then
+          table.insert(tResults, sResult)
+          tSeen[sResult] = true
+        end
+      end
+    end
+
+    -- Add all subdirectories. We don't include files as they will be added in the block below
+    local tDirs = fs.complete(sLine, sDir, false, false)
+    for i = 1, #tDirs do
+      local sResult = tDirs[i]
+      if not tSeen[sResult] then
+        table.insert(tResults, sResult)
+        tSeen[sResult] = true
+      end
+    end
+
+    -- Add programs from the path
+    local tPrograms = shell.programs()
+    for n=1,#tPrograms do
+      local sProgram = tPrograms[n]
+      if #sProgram > #sLine and string.sub(sProgram, 1, #sLine) == sLine then
+        local sResult = string.sub(sProgram, #sLine + 1)
+        if not tSeen[sResult] then
+          table.insert(tResults, sResult)
+          tSeen[sResult] = true
+        end
+      end
+    end
+
+    -- Sort and return
+    table.sort(tResults)
+    return tResults
+  end
+end
+
+local function completeProgramArgument(sProgram, nArgument, sPart, tPreviousParts)
+  local tInfo = tCompletionInfo[sProgram]
+  if tInfo then
+    return tInfo.fnComplete(shell, nArgument, sPart, tPreviousParts)
+  end
+  return nil
+end
+
+function shell.complete(sLine)
+  if type(sLine) ~= "string" then
+    error("bad argument #1 (expected string, got " .. type(sLine) .. ")", 2)
+  end
+  if #sLine > 0 then
+    local tWords = tokenise(sLine)
+    local nIndex = #tWords
+    if string.sub(sLine, #sLine, #sLine) == " " then
+      nIndex = nIndex + 1
+    end
+    if nIndex == 1 then
+      local sBit = tWords[1] or ""
+      local sPath = shell.resolveProgram(sBit)
+      if tCompletionInfo[sPath] then
+        return { " " }
+      else
+        local tResults = completeProgram(sBit)
+        for n=1,#tResults do
+          local sResult = tResults[n]
+          local sPath = shell.resolveProgram(sBit .. sResult)
+          if tCompletionInfo[sPath] then
+            tResults[n] = sResult .. " "
+          end
+        end
+        return tResults
+      end
+
+    elseif nIndex > 1 then
+      local sPath = shell.resolveProgram(tWords[1])
+      local sPart = tWords[nIndex] or ""
+      local tPreviousParts = tWords
+      tPreviousParts[nIndex] = nil
+      return completeProgramArgument(sPath , nIndex - 1, sPart, tPreviousParts)
+
+    end
+  end
+  return nil
+end
+
+function shell.completeProgram(sProgram)
+  if type(sProgram) ~= "string" then
+    error("bad argument #1 (expected string, got " .. type(sProgram) .. ")", 2)
+  end
+  return completeProgram(sProgram)
+end
+
+function shell.setCompletionFunction(sProgram, fnComplete)
+  if type(sProgram) ~= "string" then
+    error("bad argument #1 (expected string, got " .. type(sProgram) .. ")", 2)
+  end
+  if type(fnComplete) ~= "function" then
+    error("bad argument #2 (expected function, got " .. type(fnComplete) .. ")", 2)
+  end
+  tCompletionInfo[sProgram] = {
+    fnComplete = fnComplete
+  }
+end
+
+function shell.getCompletionInfo()
+  return tCompletionInfo
+end
+
+function shell.getRunningProgram()
+  if #tProgramStack > 0 then
+    return tProgramStack[#tProgramStack]
+  end
+  return nil
+end
+
+function shell.setAlias(_sCommand, _sProgram)
+  if type(_sCommand) ~= "string" then
+    error("bad argument #1 (expected string, got " .. type(_sCommand) .. ")", 2)
+  end
+  if type(_sProgram) ~= "string" then
+    error("bad argument #2 (expected string, got " .. type(_sProgram) .. ")", 2)
+  end
+  tAliases[_sCommand] = _sProgram
+end
+
+function shell.clearAlias(_sCommand)
+  if type(_sCommand) ~= "string" then
+    error("bad argument #1 (expected string, got " .. type(_sCommand) .. ")", 2)
+  end
+  tAliases[_sCommand] = nil
+end
+
+function shell.aliases()
+  -- Copy aliases
+  local tCopy = {}
+  for sAlias, sCommand in pairs(tAliases) do
+    tCopy[sAlias] = sCommand
+  end
+  return tCopy
+end
+
+function shell.history()
+  -- Read commands and execute them
+  if not history then
+    history = {}
+
+    local history_file = settings.get("mbs.shell.history_file", ".shell_history")
+    if history_file and fs.exists(history_file) then
+      local handle = fs.open(history_file, "r")
+      if handle then
+        for line in handle.readLine do history[#history + 1] = line end
+        handle.close()
+      end
+    end
+  end
+
+  return history
+end
+
+if multishell then
+  function shell.openTab(...)
+    local tWords = tokenise(...)
+    local sCommand = tWords[1]
+    if sCommand then
+      local sPath = shell.resolveProgram(sCommand)
+      if sPath == "rom/programs/shell.lua" then
+        return multishell.launch(createShellEnv("rom/programs"), sPath, table.unpack(tWords, 2))
+      elseif sPath ~= nil then
+        return multishell.launch(createShellEnv("rom/programs"), "rom/programs/shell.lua", sCommand, table.unpack(tWords, 2))
+      else
+        printError("No such program")
+      end
+    end
+  end
+
+  function shell.switchTab(nID)
+    if type(nID) ~= "number" then
+      error("bad argument #1 (expected number, got " .. type(nID) .. ")", 2)
+    end
+    multishell.setFocus(nID)
+  end
+end
+
+local tArgs = { ... }
+if #tArgs > 0 then
+  -- "shell x y z": Run the program specified on the commandline
+  shell.run(...)
+  return
+end
+
+-- "shell": Run the shell REPL
+local parent = term.current()
+local redirect = scroll_window.create(parent)
+
+local function get_first_startup()
+  if fs.exists("startup.lua") then return "startup.lua" end
+  if fs.isDir("startup")  then
+    local first = fs.list("startup")[1]
+    if first then return fs.combine("startup", first) end
+  end
+
+  return nil
+end
+
+--- Create a wrapper for various read functions, allowing the user to scroll
+-- when typing.
+local scroll_offset = nil
+fWrapper = function(fn)
+  return function(...)
+    -- Set the scroll_offset to 0 to allow scrolling
+    scroll_offset = 0
+
+    local ok, res = pcall(fn, ...)
+
+    -- And set to nil again to disable
+    if scroll_offset ~= 0 then redirect.draw(0) end
+    scroll_offset = nil
+
+    if not ok then error(res, 0) end
+    return res
+  end
+end
+
+local worker = coroutine.create(function()
+
+  -- Print the header
+  term.redirect(redirect)
+  term.setCursorPos(1, 1)
+  term.setBackgroundColor(bgColour)
+  term.setTextColour(promptColour)
+  print(os.version() .. " (+MBS)")
+  term.setTextColour(textColour)
+
+  if parentShell == nil then
+    -- If we've no parent shell. run the startup script. It's pretty unlikely,
+    -- but some mad people might be using it!
+    shell.run("/rom/startup.lua")
+  elseif parentShell.getRunningProgram() == get_first_startup() then
+    -- If we're currently in the first startup file, then run all the others.
+    local current = parentShell.getRunningProgram()
+
+    -- Run /startup or /startup.lua
+    local root_startup = shell.resolveProgram("startup")
+    if root_startup and root_startup ~= current then shell.run("/" .. root_startup) end
+
+    -- Run startup/*
+    if fs.isDir("startup") then
+      for _, file in ipairs(fs.list("startup")) do
+        local sub_startup = fs.combine("startup", file)
+        if sub_startup ~= current and not fs.isDir(sub_startup) then
+          shell.run("/" .. sub_startup)
+        end
+      end
+    end
+  end
+
+  -- The main interaction loop
+  local history = shell.history()
+  local wrapped_read = fWrapper(read)
+  while not bExit do
+    local scrollback = tonumber(settings.get("mbs.shell.scroll_max", 1e3))
+    if scrollback then redirect.setMaxScrollback(scrollback) end
+
+    term.setBackgroundColor(bgColour)
+    term.setTextColour(promptColour)
+    if term.getCursorPos() ~= 1 then print() end
+    write(shell.dir() .. "> ")
+    term.setTextColour(textColour)
+
+    local line
+    if settings.get("shell.autocomplete") then
+      line = wrapped_read(nil, history, shell.complete)
+    else
+      line = wrapped_read(nil, history)
+    end
+
+    if not line then break end
+
+    if line:match("%S") and history[#history] ~= line then
+      -- Add item to history
+      history[#history + 1] = line
+
+      -- Remove extra items from history
+      local max = tonumber(settings.get("mbs.shell.history_max", 1e4)) or 1e4
+      while #history > max do table.remove(history, 1) end
+
+      -- Write history file
+      local history_file = settings.get("mbs.shell.history_file", ".shell_history")
+      if history_file then
+        local handle = fs.open(history_file, "w")
+        if handle then
+          for i = 1, #history do handle.writeLine(history[i]) end
+          handle.close()
+        end
+      end
+    end
+
+    local _, y = term.getCursorPos()
+    redirect.setCursorThreshold(y)
+
+    local ok = shell.run(line)
+
+    term.redirect(redirect)
+    redirect.endPrivateMode(not ok)
+    redirect.draw(0)
+  end
+
+  term.redirect(parent)
+end)
+
+local ok, filter = coroutine.resume(worker)
+
+-- We run the main worker inside a coroutine, catching any potential scroll
+-- events.
+while coroutine.status(worker) ~= "dead" do
+  local event = table.pack(coroutine.yield())
+  local e = event[1]
+
+  -- Run the main REPL worker
+  if filter == nil or e == filter or e == "terminate" then
+    ok, filter = coroutine.resume(worker, table.unpack(event, 1, event.n))
+  end
+
+  -- Resize the terminal if required
+  if e == "term_resize" then
+    redirect.updateSize()
+    redirect.draw(scroll_offset or 0, true)
+  end
+
+  -- If we're in some interactive function, allow scrolling the input
+  if scroll_offset then
+    local change = 0
+    if e == "mouse_scroll" then
+      change = event[2]
+    elseif e == "key" and event[2] == keys.pageDown then
+      change = 10
+    elseif e == "key" and event[2] == keys.pageUp then
+      change = -10
+    elseif e == "key" or e == "paste" then
+      -- Reset offset if another key is pressed
+      change = -scroll_offset
+    end
+
+    if change ~= 0 and term.current() == redirect and not redirect.isPrivateMode() then
+      scroll_offset = scroll_offset + change
+      if scroll_offset > 0 then scroll_offset = 0 end
+      if scroll_offset < -redirect.getTotalHeight() then scroll_offset = -redirect.getTotalHeight() end
+      redirect.draw(scroll_offset)
+    end
+  end
+end
+
+if not ok then error(filter, 0) end
\ No newline at end of file
diff --git a/.mbs/lib/blit_window.lua b/.mbs/lib/blit_window.lua
new file mode 100644
index 0000000..39cd843
--- /dev/null
+++ b/.mbs/lib/blit_window.lua
@@ -0,0 +1,297 @@
+local colour_lookup = {}
+for i = 0, 16 do
+  colour_lookup[2 ^ i] = string.format("%x", i)
+end
+
+function create(original)
+  if not original then original = term.current() end
+
+  local text = {}
+  local text_colour = {}
+  local back_colour = {}
+  local palette = {}
+
+  local cursor_x, cursor_y = 1, 1
+
+  local cursor_blink = false
+  local cur_text_colour = "0"
+  local cur_back_colour = "f"
+
+  local sizeX, sizeY = original.getSize()
+  local color = original.isColor()
+
+  local bubble = true
+
+  local redirect = {}
+
+  if original.getPaletteColour then
+    for i = 0, 15 do
+      local c = 2 ^ i
+      palette[c] = { original.getPaletteColour(c) }
+    end
+  end
+
+  function redirect.write(writeText)
+    writeText = tostring(writeText)
+    if bubble then original.write(writeText) end
+
+    local pos = cursor_x
+
+    -- If we're off the screen then just emulate a write
+    if cursor_y > sizeY or cursor_y < 1 then
+      cursor_x = pos + #writeText
+      return
+    end
+
+    if pos + #writeText <= 1 or pos > sizeX then
+      -- If we're too far off the left then skip.
+      cursor_x = pos + #writeText
+      return
+    elseif pos < 1 then
+      -- Adjust text to fit on screen starting at one.
+      writeText = string.sub(writeText, math.abs(cursor_x) + 2)
+      pos = 1
+    end
+
+    local lineText = text[cursor_y]
+    local lineColor = text_colour[cursor_y]
+    local lineBack = back_colour[cursor_y]
+    local preStop = pos - 1
+    local preStart = math.min(1, preStop)
+    local postStart = pos + string.len(writeText)
+    local postStop = sizeX
+    local sub, rep = string.sub, string.rep
+
+    text[cursor_y] = sub(lineText, preStart, preStop)..writeText..sub(lineText, postStart, postStop)
+    text_colour[cursor_y] = sub(lineColor, preStart, preStop)..rep(cur_text_colour, #writeText)..sub(lineColor, postStart, postStop)
+    back_colour[cursor_y] = sub(lineBack, preStart, preStop)..rep(cur_back_colour, #writeText)..sub(lineBack, postStart, postStop)
+    cursor_x = pos + string.len(writeText)
+  end
+
+  function redirect.blit(writeText, writeFore, writeBack)
+    if type(writeText) ~= "string" then error("bad argument #1 (expected string, got " .. type(writeText) .. ")", 2) end
+    if type(writeFore) ~= "string" then error("bad argument #2 (expected string, got " .. type(writeFore) .. ")", 2) end
+    if type(writeBack) ~= "string" then error("bad argument #3 (expected string, got " .. type(writeBack) .. ")", 2) end
+    if #writeFore ~= #writeText or #writeBack ~= #writeText then error("Arguments must be the same length", 2) end
+
+    if bubble then original.blit(writeText, writeFore, writeBack) end
+    local pos = cursor_x
+
+    -- If we're off the screen then just emulate a write
+    if cursor_y > sizeY or cursor_y < 1 then
+      cursor_x = pos + #writeText
+      return
+    end
+
+    if pos + #writeText <= 1 then
+      --skip entirely.
+      cursor_x = pos + #writeText
+      return
+    elseif pos < 1 then
+      --adjust text to fit on screen starting at one.
+      writeText = string.sub(writeText, math.abs(cursor_x) + 2)
+      writeFore = string.sub(writeFore, math.abs(cursor_x) + 2)
+      writeBack = string.sub(writeBack, math.abs(cursor_x) + 2)
+      cursor_x = 1
+    elseif pos > sizeX then
+      --if we're off the edge to the right, skip entirely.
+      cursor_x = pos + #writeText
+      return
+    end
+
+    local lineText = text[cursor_y]
+    local lineColor = text_colour[cursor_y]
+    local lineBack = back_colour[cursor_y]
+    local preStop = cursor_x - 1
+    local preStart = math.min(1, preStop)
+    local postStart = cursor_x + string.len(writeText)
+    local postStop = sizeX
+    local sub = string.sub
+
+    text[cursor_y] = sub(lineText, preStart, preStop)..writeText..sub(lineText, postStart, postStop)
+    text_colour[cursor_y] = sub(lineColor, preStart, preStop)..writeFore..sub(lineColor, postStart, postStop)
+    back_colour[cursor_y] = sub(lineBack, preStart, preStop)..writeBack..sub(lineBack, postStart, postStop)
+    cursor_x = pos + string.len(writeText)
+  end
+
+  function redirect.clear()
+    for i = 1, sizeY do
+      text[i] = string.rep(" ", sizeX)
+      text_colour[i] = string.rep(cur_text_colour, sizeX)
+      back_colour[i] = string.rep(cur_back_colour, sizeX)
+    end
+
+    if bubble then return original.clear() end
+  end
+
+  function redirect.clearLine()
+    -- If we're off the screen then just emulate a clearLine
+    if cursor_y > sizeY or cursor_y < 1 then
+      return
+    end
+
+    text[cursor_y] = string.rep(" ", sizeX)
+    text_colour[cursor_y] = string.rep(cur_text_colour, sizeX)
+    back_colour[cursor_y] = string.rep(cur_back_colour, sizeX)
+
+    if bubble then return original.clearLine() end
+  end
+
+  function redirect.getCursorPos()
+    return cursor_x, cursor_y
+  end
+
+  function redirect.setCursorPos(x, y)
+    if type(x) ~= "number" then error("bad argument #1 (expected number, got " .. type(x) .. ")", 2) end
+    if type(y) ~= "number" then error("bad argument #2 (expected number, got " .. type(y) .. ")", 2) end
+
+    cursor_x = math.floor(x)
+    cursor_y = math.floor(y)
+    if bubble then return original.setCursorPos(x, y) end
+  end
+
+  function redirect.setCursorBlink(b)
+    cursor_blink = b
+    if bubble then return original.setCursorBlink(b) end
+  end
+
+  function redirect.getSize()
+    return sizeX, sizeY
+  end
+
+  function redirect.scroll(n)
+    if type(n) ~= "number" then error("bad argument #1 (expected number, got " .. type(n) .. ")", 2) end
+
+    local empty_text = string.rep(" ", sizeX)
+    local empty_text_colour = string.rep(cur_text_colour, sizeX)
+    local empty_back_colour = string.rep(cur_back_colour, sizeX)
+    if n > 0 then
+      for i = 1, sizeY do
+        text[i] = text[i + n] or empty_text
+        text_colour[i] = text_colour[i + n] or empty_text_colour
+        back_colour[i] = back_colour[i + n] or empty_back_colour
+      end
+    elseif n < 0 then
+      for i = sizeY, 1, -1 do
+        text[i] = text[i + n] or empty_text
+        text_colour[i] = text_colour[i + n] or empty_text_colour
+        back_colour[i] = back_colour[i + n] or empty_back_colour
+      end
+    end
+
+    if bubble then return original.scroll(n) end
+  end
+
+  function redirect.setTextColour(clr)
+    if type(clr) ~= "number" then error("bad argument #1 (expected number, got " .. type(clr) .. ")", 2) end
+    cur_text_colour = colour_lookup[clr] or error("Invalid colour (got " .. clr .. ")" , 2)
+    if bubble then return original.setTextColour(clr) end
+  end
+  redirect.setTextColor = redirect.setTextColour
+
+  function redirect.setBackgroundColour(clr)
+    if type(clr) ~= "number" then error("bad argument #1 (expected number, got " .. type(clr) .. ")", 2) end
+    cur_back_colour = colour_lookup[clr] or error("Invalid colour (got " .. clr .. ")" , 2)
+    if bubble then return original.setBackgroundColour(clr) end
+  end
+  redirect.setBackgroundColor = redirect.setBackgroundColour
+
+  function redirect.isColour()
+    return color == true
+  end
+  redirect.isColor = redirect.isColour
+
+  function redirect.getTextColour()
+    return 2 ^ tonumber(cur_text_colour, 16)
+  end
+  redirect.getTextColor = redirect.getTextColour
+
+  function redirect.getBackgroundColour()
+    return 2 ^ tonumber(cur_back_colour, 16)
+  end
+  redirect.getBackgroundColor = redirect.getBackgroundColour
+
+  if original.getPaletteColour then
+    function redirect.setPaletteColour(colour, r, g, b)
+      local palcol = palette[colour]
+      if not palcol then error("Invalid colour (got " .. tostring(colour) .. ")", 2) end
+      if type(r) == "number" and g == nil and b == nil then
+          palcol[1], palcol[2], palcol[3] = colours.rgb8(r)
+      else
+          if type(r) ~= "number" then error("bad argument #2 (expected number, got " .. type(r) .. ")", 2) end
+          if type(g) ~= "number" then error("bad argument #3 (expected number, got " .. type(g) .. ")", 2) end
+          if type(b) ~= "number" then error("bad argument #4 (expected number, got " .. type(b) .. ")", 2) end
+
+          palcol[1], palcol[2], palcol[3] = r, g, b
+      end
+
+      if bubble then return original.setPaletteColour(colour, r, g, b) end
+    end
+    redirect.setPaletteColor = redirect.setPaletteColour
+
+    function redirect.getPaletteColour(colour)
+      local palcol = palette[colour]
+      if not palcol then error("Invalid colour (got " .. tostring(colour) .. ")", 2) end
+      return palcol[1], palcol[2], palcol[3]
+    end
+    redirect.getPaletteColor = redirect.getPaletteColour
+  end
+
+  function redirect.draw(target)
+    if not target then target = original end
+
+    if target.getPaletteColour then
+      for colour, pal in pairs(palette) do
+        target.setPaletteColour(colour, pal[1], pal[2], pal[3])
+      end
+    end
+
+    for i=1, sizeY do
+      target.setCursorPos(1,i)
+      target.blit(text[i], text_colour[i], back_colour[i])
+    end
+
+    target.setCursorPos(cursor_x, cursor_y)
+    target.setTextColour(2 ^ tonumber(cur_text_colour, 16))
+    target.setBackgroundColor(2 ^ tonumber(cur_back_colour, 16))
+    target.setCursorBlink(cursor_blink)
+  end
+
+  function redirect.bubble(b)
+    bubble = b
+  end
+
+  function redirect.updateSize()
+    local new_x, new_y = original.getSize()
+    if new_x == sizeX and new_y == sizeY then return end
+
+    -- For any existing lines, trim them
+    for y = 1, sizeY do
+      if new_x < sizeX then
+        text[y] = text[y]:sub(1, new_x)
+        text_colour[y] = text_colour[y]:sub(1, new_x)
+        back_colour[y] = back_colour[y]:sub(1, new_x)
+      elseif new_x > sizeX then
+        text[y] = text[y] .. (" "):rep(new_x - sizeX)
+        text_colour[y] = text_colour[y] .. (cur_text_colour):rep(new_x - sizeX)
+        back_colour[y] = back_colour[y] .. (cur_back_colour):rep(new_x - sizeX)
+      end
+    end
+
+    -- Add any new lines we might need.
+    local text_line = (" "):rep(new_x)
+    local fore_line = (cur_text_colour):rep(new_x)
+    local back_line = (cur_back_colour):rep(new_x)
+    for y = sizeY + 1, new_y do
+      text[y] = text_line
+      text_colour[y] = fore_line
+      back_colour[y] = back_line
+    end
+
+    sizeX = new_x
+    sizeY = new_y
+  end
+
+  redirect.clear()
+  return redirect
+end
\ No newline at end of file
diff --git a/.mbs/lib/readline.lua b/.mbs/lib/readline.lua
new file mode 100644
index 0000000..ba322a6
--- /dev/null
+++ b/.mbs/lib/readline.lua
@@ -0,0 +1,506 @@
+
+--- A mapping of colours, to aid reading settings.
+local colour_table = { }
+
+for k, v in pairs(colours) do
+  if type(v) == "number" then colour_table[k] = v end
+end
+
+for k, v in pairs(colors) do
+  if type(v) == "number" then colour_table[k] = v end
+end
+
+--- Keys which are used in combinations involving the "meta" key.
+local meta_keys = "ulcdbf"
+
+--- Clamp a [value] within a range
+local function clamp(value, min, max)
+  if value < min then return min end
+  if value > max then return max end
+  return value
+end
+
+--- Verify a [tbl] has a [key] of nil or the given [type]
+local type = type
+local function check_key(tbl, key, ty)
+   local actual_type = type(tbl[key])
+   if actual_type ~= "nil" and actual_type ~= ty then
+    error(("bad key %s (expected %s, got %s)"):format(key, ty, actual_type), 3)
+  end
+end
+
+function read(opts)
+  if opts == nil then
+    opts = {}
+  elseif type(opts) ~= "table" then
+    error("bad argument #1 (expected table, got " .. type(opts) .. ")", 2)
+  end
+
+  check_key(opts, "replace_char", "string") -- Character to show instead
+  check_key(opts, "history", "table") -- List of previous items
+  check_key(opts, "complete", "function") -- Completion function
+  check_key(opts, "default", "string") -- Initial string
+  check_key(opts, "complete_fg", "number") -- Foreground for completion
+  check_key(opts, "complete_bg", "number") -- Background for completion
+
+  -- Highlight function: (line: string, start: number) -> (end: number, colour:colour)
+  check_key(opts, "highlight", "function")
+
+  local w = term.getSize()
+  local sx = term.getCursorPos()
+
+  local sLine = opts.default or ""
+  local nPos, nScroll = #sLine, 0
+  local tKillRing, nKillRing = {}, 0
+
+  local nHistoryPos
+  local tDown = {}
+  local nMod = 0
+  local replace_char = opts.replace_char and opts.replace_char:sub(1, 1)
+  local complete_fg = opts.complete_fg or colour_table[settings.get("mbs.readline.complete_fg")] or -1
+  local complete_bg = opts.complete_bg or colour_table[settings.get("mbs.readline.complete_bg")] or -1
+
+  local tCompletions
+  local nCompletion
+  local function recomplete()
+    if opts.complete and nPos == #sLine then
+      tCompletions = opts.complete(sLine)
+      if tCompletions and #tCompletions > 0 then
+        nCompletion = 1
+      else
+        nCompletion = nil
+      end
+    else
+      tCompletions = nil
+      nCompletion = nil
+    end
+  end
+
+  local function uncomplete()
+    tCompletions = nil
+    nCompletion = nil
+  end
+
+  local function updateModifier()
+    nMod = 0
+    if tDown[keys.leftCtrl] or tDown[keys.rightCtrl] then nMod = nMod + 1 end
+    if tDown[keys.leftAlt] or tDown[keys.rightAlt]   then nMod = nMod + 2 end
+  end
+
+  local function nextWord()
+    -- Attempt to find the position of the next word
+    local nOffset = sLine:find("%w%W", nPos + 1)
+    if nOffset then return nOffset else return #sLine end
+  end
+
+  local function prevWord()
+    -- Attempt to find the position of the previous word
+    local nOffset = 1
+    while nOffset <= #sLine do
+      local nNext = sLine:find("%W%w", nOffset)
+      if nNext and nNext < nPos then
+        nOffset = nNext + 1
+      else
+        break
+      end
+    end
+    return nOffset - 1
+  end
+
+  local function redraw(_bClear)
+    local cursor_pos = nPos - nScroll
+    if sx + cursor_pos >= w then
+      -- We've moved beyond the RHS, ensure we're on the edge.
+      nScroll = sx + nPos - w
+    elseif cursor_pos < 0 then
+      -- We've moved beyond the LHS, ensure we're on the edge.
+      nScroll = nPos
+    end
+
+    local _, cy = term.getCursorPos()
+    term.setCursorPos(sx, cy)
+    local sReplace = (_bClear and " ") or replace_char
+
+    if opts.highlight and not _bClear then
+      -- We've a highlighting function: step through each line of input
+      local old_col = term.getTextColor()
+      local hl_pos, hl_max, hl_col = 1, #sLine, old_col
+      while hl_pos <= hl_max do
+        local next_pos, next_col = opts.highlight(sLine, hl_pos)
+        if next_pos < hl_pos then error("Highlighting function consumed no input") end
+
+        if next_pos >= nScroll + 1 then
+          if next_col ~= hl_col then term.setTextColor(next_col) hl_col = next_col end
+          if sReplace then
+            term.write(string.rep(sReplace, next_pos - math.max(nScroll + 1, hl_pos) + 1))
+          else
+            term.write(string.sub(sLine, math.max(nScroll + 1, hl_pos), next_pos))
+          end
+        end
+
+        hl_pos = next_pos + 1
+      end
+      term.setTextColor(old_col)
+    else
+      -- If we've no highlighting function, we can go the "fast" path.
+      if sReplace then
+        term.write(string.rep(sReplace, math.max(#sLine - nScroll, 0)))
+      else
+        term.write(string.sub(sLine, nScroll + 1))
+      end
+    end
+
+    if nCompletion then
+      local sCompletion = tCompletions[ nCompletion ]
+      local oldText, oldBg
+      if not _bClear then
+        oldText = term.getTextColor()
+        oldBg = term.getBackgroundColor()
+        if complete_fg > -1 then term.setTextColor(complete_fg) end
+        if complete_bg > -1 then term.setBackgroundColor(complete_bg) end
+      end
+      if sReplace then
+        term.write(string.rep(sReplace, #sCompletion))
+      else
+        term.write(sCompletion)
+      end
+      if not _bClear then
+        term.setTextColor(oldText)
+        term.setBackgroundColor(oldBg)
+      end
+    end
+
+    term.setCursorPos(sx + nPos - nScroll, cy)
+  end
+
+  local function nsub(start, fin)
+    if start < 1 or fin < start then return "" end
+    return sLine:sub(start, fin)
+  end
+
+  local function clear()
+    redraw(true)
+  end
+
+  local function kill(text)
+    if #text == "" then return end
+    nKillRing = nKillRing + 1
+    tKillRing[nKillRing] = text
+  end
+
+  local function acceptCompletion()
+    if nCompletion then
+      -- Clear
+      clear()
+
+      -- Find the common prefix of all the other suggestions which start with the same letter as the current one
+      local sCompletion = tCompletions[ nCompletion ]
+      sLine = sLine .. sCompletion
+      nPos = #sLine
+
+      -- Redraw
+      recomplete()
+      redraw()
+    end
+  end
+
+  term.setCursorBlink(true)
+  recomplete()
+  redraw()
+  while true do
+    local sEvent, param, param1, param2 = os.pullEvent()
+    if sEvent == "char" and (nMod == 0 or nMod == 3 or (nMod == 2 and not meta_keys:find(param, 1, true))) then
+      -- Typed key
+      -- Alt+X will queue a char event, so we limit ourselves to cases where
+      -- no modifier is used, or Ctrl+Alt are (equivalent to AltGr), or the Alt
+      -- key is used and we have no known combination.
+      clear()
+      sLine = string.sub(sLine, 1, nPos) .. param .. string.sub(sLine, nPos + 1)
+      nPos = nPos + 1
+      recomplete()
+      redraw()
+    elseif sEvent == "paste" then
+      -- Pasted text
+      clear()
+      sLine = string.sub(sLine, 1, nPos) .. param .. string.sub(sLine, nPos + 1)
+      nPos = nPos + #param
+      recomplete()
+      redraw()
+    elseif sEvent == "key" then
+      -- All keybindigns within the read loop.
+      -- IMPORTANT: Please update the meta_keys variable up top. Ideally we'd
+      -- make each function operate on a state, and run outside the loop, but
+      -- this will do for now.
+      if param == keys.leftCtrl or param == keys.rightCtrl or param == keys.leftAlt or param == keys.rightAlt then
+        tDown[param] = true
+        updateModifier()
+      elseif param == keys.enter then
+        -- Enter
+        if nCompletion then
+          clear()
+          uncomplete()
+          redraw()
+        end
+        break
+
+      -- Moving through text/completions
+      elseif nMod == 1 and param == keys.d then
+        -- End of stream, abort
+        if nCompletion then
+          clear()
+          uncomplete()
+          redraw()
+        end
+        sLine = nil
+        nPos = 0
+        break
+      elseif (nMod == 0 and param == keys.left) or (nMod == 1 and param == keys.b) then
+        -- Left
+        if nPos > 0 then
+          clear()
+          nPos = nPos - 1
+          recomplete()
+          redraw()
+        end
+      elseif (nMod == 0 and param == keys.right) or (nMod == 1 and param == keys.f) then
+        -- Right
+        if nPos < #sLine then
+          -- Move right
+          clear()
+          nPos = nPos + 1
+          recomplete()
+          redraw()
+        else
+          -- Accept autocomplete
+          acceptCompletion()
+        end
+      elseif nMod == 2 and param == keys.b then
+        -- Word left
+        local nNewPos = prevWord()
+        if nNewPos ~= nPos then
+          clear()
+          nPos = nNewPos
+          recomplete()
+          redraw()
+        end
+      elseif nMod == 2 and param == keys.f then
+        -- Word right
+        local nNewPos = nextWord()
+        if nNewPos ~= nPos then
+          clear()
+          nPos = nNewPos
+          recomplete()
+          redraw()
+        end
+      elseif (nMod == 0 and (param == keys.up or param == keys.down))
+          or (nMod == 1 and (param == keys.p or param == keys.n)) then
+        -- Up or down
+        if nCompletion then
+          -- Cycle completions
+          clear()
+          if param == keys.up or param == keys.p then
+            nCompletion = nCompletion - 1
+            if nCompletion < 1 then
+              nCompletion = #tCompletions
+            end
+          elseif param == keys.down or param == keys.n then
+            nCompletion = nCompletion + 1
+            if nCompletion > #tCompletions then
+              nCompletion = 1
+            end
+          end
+          redraw()
+        elseif opts.history then
+          -- Cycle history
+          clear()
+          if param == keys.up or param == keys.p then
+            -- Up
+            if nHistoryPos == nil then
+              if #opts.history > 0 then
+                nHistoryPos = #opts.history
+              end
+            elseif nHistoryPos > 1 then
+              nHistoryPos = nHistoryPos - 1
+            end
+          elseif param == keys.down or param == keys.n then
+            -- Down
+            if nHistoryPos == #opts.history then
+              nHistoryPos = nil
+            elseif nHistoryPos ~= nil then
+              nHistoryPos = nHistoryPos + 1
+            end
+          end
+          if nHistoryPos then
+            sLine = opts.history[nHistoryPos]
+            nPos, nScroll = #sLine, 0
+          else
+            sLine = ""
+            nPos, nScroll = 0, 0
+          end
+          uncomplete()
+          redraw()
+        end
+      elseif (nMod == 0 and param == keys.home)
+          or (nMod == 1 and param == keys.a) then
+        -- Home
+        if nPos > 0 then
+          clear()
+          nPos = 0
+          recomplete()
+          redraw()
+        end
+      elseif (nMod == 0 and param == keys["end"])
+          or (nMod == 1 and param == keys.e) then
+        -- End
+        if nPos < #sLine then
+          clear()
+          nPos = #sLine
+          recomplete()
+          redraw()
+        end
+      -- Changing text
+      elseif nMod == 1 and param == keys.t then
+        -- Transpose char
+        local prev, cur
+        if nPos == #sLine then prev, cur = nPos - 1, nPos
+        elseif nPos == 0 then prev, cur = 1, 2
+        else prev, cur = nPos, nPos + 1
+        end
+
+        sLine = nsub(1, prev - 1) .. nsub(cur, cur) .. nsub(prev, prev) .. nsub(cur + 1, #sLine)
+        nPos = math.min(#sLine, cur)
+
+        -- We need the clear to remove the completion
+        clear(); recomplete(); redraw()
+      elseif nMod == 2 and param == keys.u then
+        -- Upcase word
+        if nPos < #sLine then
+          local nNext = nextWord()
+          sLine = nsub(1, nPos) .. nsub(nPos + 1, nNext):upper() .. nsub(nNext + 1, #sLine)
+          nPos = nNext
+          clear(); recomplete(); redraw()
+        end
+      elseif nMod == 2 and param == keys.l then
+        -- Lowercase word
+        if nPos < #sLine then
+          local nNext = nextWord()
+          sLine = nsub(1, nPos) .. nsub(nPos + 1, nNext):lower() .. nsub(nNext + 1, #sLine)
+          nPos = nNext
+          clear(); recomplete(); redraw()
+        end
+      elseif nMod == 2 and param == keys.c then
+        -- Capitalize word
+        if nPos < #sLine then
+          local nNext = nextWord()
+          sLine = nsub(1, nPos) .. nsub(nPos + 1, nPos + 1):upper()
+               .. nsub(nPos + 2, nNext):lower() .. nsub(nNext + 1, #sLine)
+          nPos = nNext
+          clear(); recomplete(); redraw()
+        end
+
+      -- Killing text
+      elseif nMod == 0 and param == keys.backspace then
+        -- Backspace
+        if nPos > 0 then
+          clear()
+          sLine = string.sub(sLine, 1, nPos - 1) .. string.sub(sLine, nPos + 1)
+          nPos = nPos - 1
+          if nScroll > 0 then nScroll = nScroll - 1 end
+          recomplete()
+          redraw()
+        end
+      elseif nMod == 0 and param == keys.delete then
+        -- Delete
+        if nPos < #sLine then
+          clear()
+          sLine = string.sub(sLine, 1, nPos) .. string.sub(sLine, nPos + 2)
+          recomplete()
+          redraw()
+        end
+      elseif nMod == 1 and param == keys.u then
+        -- Delete from cursor to beginning of line
+        if nPos > 0 then
+          clear()
+          kill(sLine:sub(1, nPos))
+          sLine = sLine:sub(nPos + 1)
+          nPos = 0
+          recomplete(); redraw()
+        end
+      elseif nMod == 1 and param == keys.k then
+        -- Delete from cursor to end of line
+        if nPos < #sLine then
+          clear()
+          kill(sLine:sub(nPos + 1))
+          sLine = sLine:sub(1, nPos)
+          nPos = #sLine
+          recomplete(); redraw()
+        end
+      elseif nMod == 2 and param == keys.d then
+        -- Delete from cursor to end of next word
+        if nPos < #sLine then
+            local nNext = nextWord()
+            if nNext ~= nPos then
+              clear()
+              kill(sLine:sub(nPos + 1, nNext))
+              sLine = sLine:sub(1, nPos) .. sLine:sub(nNext + 1)
+              recomplete(); redraw()
+            end
+        end
+      elseif nMod == 1 and param == keys.w then
+        -- Delete from cursor to beginning of previous word
+        if nPos > 0 then
+          local nPrev = prevWord(nPos)
+          if nPrev ~= nPos then
+            clear()
+            kill(sLine:sub(nPrev + 1, nPos))
+            sLine = sLine:sub(1, nPrev) .. sLine:sub(nPos + 1)
+            nPos = nPrev
+            recomplete(); redraw()
+          end
+        end
+      elseif nMod == 1 and param == keys.y then
+        local insert = tKillRing[nKillRing]
+        if insert then
+          clear()
+          sLine = sLine:sub(1, nPos) .. insert .. sLine:sub(nPos + 1)
+          nPos = nPos + #insert
+          recomplete(); redraw()
+        end
+      -- Misc
+      elseif nMod == 0 and param == keys.tab then
+        -- Tab (accept autocomplete)
+        acceptCompletion()
+      end
+    elseif sEvent == "key_up" then
+      -- Update the status of the modifier flag
+      if param == keys.leftCtrl or param == keys.rightCtrl
+      or param == keys.leftAlt or param == keys.rightAlt then
+        tDown[param] = false
+        updateModifier()
+      end
+    elseif sEvent == "mouse_click" or sEvent == "mouse_drag" and param == 1 then
+      local _, cy = term.getCursorPos()
+      if param2 == cy then
+        -- We first clamp the x position with in the start and end points
+        -- to ensure we don't scroll beyond the visible region.
+        local x = clamp(param1, sx, w)
+
+        -- Then ensure we don't scroll beyond the current line
+        nPos = clamp(nScroll + x - sx, 0, #sLine)
+
+        redraw()
+      end
+    elseif sEvent == "term_resize" then
+      -- Terminal resized
+      w = term.getSize()
+      redraw()
+    end
+  end
+
+  local _, cy = term.getCursorPos()
+  term.setCursorBlink(false)
+  term.setCursorPos(w + 1, cy)
+  print()
+
+  return sLine
+end
\ No newline at end of file
diff --git a/.mbs/lib/scroll_window.lua b/.mbs/lib/scroll_window.lua
new file mode 100644
index 0000000..75a6fb1
--- /dev/null
+++ b/.mbs/lib/scroll_window.lua
@@ -0,0 +1,459 @@
+local type = type
+
+local colour_lookup = {}
+for i = 0, 16 do
+  colour_lookup[2 ^ i] = string.format("%x", i)
+end
+
+function create(original)
+  if not original then original = term.current() end
+
+  local text = {}
+  local text_colour = {}
+  local back_colour = {}
+  local palette = {}
+
+  local cursor_x, cursor_y = 1, 1
+
+  local scroll_offset = 0
+  local scroll_cursor_y = cursor_y
+
+  local cursor_blink = false
+  local cur_text_colour = "0"
+  local cur_back_colour = "f"
+
+  local sizeX, sizeY = original.getSize()
+  local color = original.isColor()
+
+  local max_scrollback = 100
+  local bubble, delegate = true, nil
+
+  local cursor_threshold = 0
+
+  local redirect = {}
+
+  if original.getPaletteColour then
+    for i = 0, 15 do
+      local c = 2 ^ i
+      palette[c] = { original.getPaletteColour(c) }
+    end
+  end
+
+  local function trim()
+    if max_scrollback > -1 then
+      while scroll_offset > max_scrollback do
+        table.remove(text, 1)
+        table.remove(text_colour, 1)
+        table.remove(back_colour, 1)
+        scroll_offset = scroll_offset - 1
+      end
+    end
+    scroll_cursor_y = scroll_offset + cursor_y
+  end
+
+  function redirect.write(writeText)
+    if delegate then return delegate.write(writeText) end
+
+    writeText = tostring(writeText)
+    if bubble then original.write(writeText) end
+
+    local pos = cursor_x
+
+    -- If we're off the screen then just emulate a write
+    if cursor_y > sizeY or cursor_y < 1 then
+      cursor_x = pos + #writeText
+      return
+    end
+
+    if pos + #writeText <= 1 or pos > sizeX then
+      -- If we're too far off the left then skip.
+      cursor_x = pos + #writeText
+      return
+    elseif pos < 1 then
+      -- Adjust text to fit on screen starting at one.
+      writeText = string.sub(writeText, -pos + 2)
+      pos = 1
+    end
+
+    local lineText = text[scroll_cursor_y]
+    local lineColor = text_colour[scroll_cursor_y]
+    local lineBack = back_colour[scroll_cursor_y]
+    local preStop = pos - 1
+    local preStart = math.min(1, preStop)
+    local postStart = pos + string.len(writeText)
+    local postStop = sizeX
+    local sub, rep = string.sub, string.rep
+
+    text[scroll_cursor_y] = sub(lineText, preStart, preStop)..writeText..sub(lineText, postStart, postStop)
+    text_colour[scroll_cursor_y] = sub(lineColor, preStart, preStop)..rep(cur_text_colour, #writeText)..sub(lineColor, postStart, postStop)
+    back_colour[scroll_cursor_y] = sub(lineBack, preStart, preStop)..rep(cur_back_colour, #writeText)..sub(lineBack, postStart, postStop)
+    cursor_x = pos + string.len(writeText)
+  end
+
+  function redirect.blit(writeText, writeFore, writeBack)
+    if delegate then return delegate.blit(writeText, writeFore, writeBack) end
+
+    if type(writeText) ~= "string" then error("bad argument #1 (expected string, got " .. type(writeText) .. ")", 2) end
+    if type(writeFore) ~= "string" then error("bad argument #2 (expected string, got " .. type(writeFore) .. ")", 2) end
+    if type(writeBack) ~= "string" then error("bad argument #3 (expected string, got " .. type(writeBack) .. ")", 2) end
+    if #writeFore ~= #writeText or #writeBack ~= #writeText then error("Arguments must be the same length", 2) end
+
+    if bubble then original.blit(writeText, writeFore, writeBack) end
+
+    local pos = cursor_x
+
+    -- If we're off the screen then just emulate a write
+    if cursor_y > sizeY or cursor_y < 1 then
+      cursor_x = pos + #writeText
+      return
+    end
+
+    if pos + #writeText <= 1 then
+      --skip entirely.
+      cursor_x = pos + #writeText
+      return
+    elseif pos < 1 then
+      --adjust text to fit on screen starting at one.
+      writeText = string.sub(writeText, math.abs(cursor_x) + 2)
+      writeFore = string.sub(writeFore, math.abs(cursor_x) + 2)
+      writeBack = string.sub(writeBack, math.abs(cursor_x) + 2)
+      cursor_x = 1
+    elseif pos > sizeX then
+      --if we're off the edge to the right, skip entirely.
+      cursor_x = pos + #writeText
+      return
+    else
+      writeText = writeText
+    end
+
+    local lineText = text[scroll_cursor_y]
+    local lineColor = text_colour[scroll_cursor_y]
+    local lineBack = back_colour[scroll_cursor_y]
+    local preStop = cursor_x - 1
+    local preStart = math.min(1, preStop)
+    local postStart = cursor_x + string.len(writeText)
+    local postStop = sizeX
+    local sub = string.sub
+
+    text[scroll_cursor_y] = sub(lineText, preStart, preStop)..writeText..sub(lineText, postStart, postStop)
+    text_colour[scroll_cursor_y] = sub(lineColor, preStart, preStop)..writeFore..sub(lineColor, postStart, postStop)
+    back_colour[scroll_cursor_y] = sub(lineBack, preStart, preStop)..writeBack..sub(lineBack, postStart, postStop)
+    cursor_x = pos + #writeText
+  end
+
+  function redirect.clear()
+    if delegate then return delegate.clear() end
+
+    if cursor_threshold > 0 then
+      return redirect.beginPrivateMode().clear()
+    end
+
+    local text_line = (" "):rep(sizeX)
+    local fore_line = (cur_text_colour):rep(sizeX)
+    local back_line = (cur_back_colour):rep(sizeX)
+
+    for i = scroll_offset + 1, sizeY + scroll_offset do
+      text[i] = text_line
+      text_colour[i] = fore_line
+      back_colour[i] = back_line
+    end
+
+    if bubble then return original.clear() end
+  end
+  function redirect.clearLine()
+    if delegate then return delegate.clearLine() end
+
+    -- If we're off the screen then just emulate a clearLine
+    if cursor_y > sizeY or cursor_y < 1 then
+      return
+    end
+
+    text[scroll_cursor_y] = string.rep(" ", sizeX)
+    text_colour[scroll_cursor_y] = string.rep(cur_text_colour, sizeX)
+    back_colour[scroll_cursor_y] = string.rep(cur_back_colour, sizeX)
+
+    if bubble then return original.clearLine() end
+  end
+
+  function redirect.getCursorPos()
+    if delegate then return delegate.getCursorPos() end
+    return cursor_x, cursor_y
+  end
+
+  function redirect.setCursorPos(x, y)
+    if delegate then return delegate.setCursorPos(x, y) end
+
+    if type(x) ~= "number" then error("bad argument #1 (expected number, got " .. type(x) .. ")", 2) end
+    if type(y) ~= "number" then error("bad argument #2 (expected number, got " .. type(y) .. ")", 2) end
+
+    local new_y = math.floor(y)
+    if new_y >= 1 and new_y < cursor_threshold then
+      -- If we're writing within a protected region then start a private buffer
+      return redirect.beginPrivateMode().setCursorPos(x, y)
+    end
+
+    cursor_x = math.floor(x)
+    cursor_y = new_y
+    scroll_cursor_y = new_y + scroll_offset
+
+    if bubble then return original.setCursorPos(x, y) end
+  end
+
+  function redirect.setCursorBlink(b)
+    if delegate then return delegate.setCursorBlink(b) end
+
+    if type(b) ~= "boolean" then error("bad argument #1 (expected boolean, got " .. type(b) .. ")", 2) end
+
+    cursor_blink = b
+    if bubble then return original.setCursorBlink(b) end
+  end
+
+  function redirect.getSize()
+    if delegate then return delegate.getSize() end
+
+    return sizeX, sizeY
+  end
+
+  function redirect.scroll(n)
+    if delegate then return delegate.scroll(n) end
+
+    if type(n) ~= "number" then error("bad argument #1 (expected number, got " .. type(n) .. ")", 2) end
+
+    if n > 0 then
+      scroll_offset = scroll_offset + n
+      for i = sizeY + scroll_offset - n + 1, sizeY + scroll_offset do
+        text[i] = string.rep(" ", sizeX)
+        text_colour[i] = string.rep(cur_text_colour, sizeX)
+        back_colour[i] = string.rep(cur_back_colour, sizeX)
+      end
+
+      trim()
+    elseif n < 0 then
+      for i = sizeY + scroll_cursor_y, math.abs(n) + 1 + scroll_cursor_y, -1 do
+        if text[i + n] then
+          text[i] = text[i + n]
+          text_colour[i] = text_colour[i + n]
+          back_colour[i] = back_colour[i + n]
+        end
+      end
+
+      for i = scroll_cursor_y, math.abs(n) + scroll_cursor_y do
+        text[i] = string.rep(" ", sizeX)
+        text_colour[i] = string.rep(cur_text_colour, sizeX)
+        back_colour[i] = string.rep(cur_back_colour, sizeX)
+      end
+    end
+
+    cursor_threshold = cursor_threshold - n
+
+    if bubble then return original.scroll(n) end
+  end
+
+  function redirect.setTextColour(clr)
+    if delegate then return delegate.setTextColour(clr) end
+
+    if type(clr) ~= "number" then error("bad argument #1 (expected number, got " .. type(clr) .. ")", 2) end
+    cur_text_colour = colour_lookup[clr] or error("Invalid colour (got " .. clr .. ")" , 2)
+    if bubble then return original.setTextColour(clr) end
+  end
+  redirect.setTextColor = redirect.setTextColour
+
+  function redirect.setBackgroundColour(clr)
+    if delegate then return delegate.setBackgroundColour(clr) end
+
+    if type(clr) ~= "number" then error("bad argument #1 (expected number, got " .. type(clr) .. ")", 2) end
+    cur_back_colour = colour_lookup[clr] or error("Invalid colour (got " .. clr .. ")" , 2)
+    if bubble then return original.setBackgroundColour(clr) end
+  end
+  redirect.setBackgroundColor = redirect.setBackgroundColour
+
+  function redirect.isColour()
+    if delegate then return delegate.isColour() end
+    return color == true
+  end
+  redirect.isColor = redirect.isColour
+
+  function redirect.getTextColour()
+    if delegate then return delegate.getTextColour() end
+    return 2 ^ tonumber(cur_text_colour, 16)
+  end
+  redirect.getTextColor = redirect.getTextColour
+
+  function redirect.getBackgroundColour()
+    if delegate then return delegate.getBackgroundColour() end
+    return 2 ^ tonumber(cur_back_colour, 16)
+  end
+  redirect.getBackgroundColor = redirect.getBackgroundColour
+
+  if original.getPaletteColour then
+    function redirect.setPaletteColour(colour, r, g, b)
+      if delegate then return delegate.setPaletteColour(colour, r, g, b) end
+
+      local palcol = palette[colour]
+      if not palcol then error("Invalid colour (got " .. tostring(colour) .. ")", 2) end
+      if type(r) == "number" and g == nil and b == nil then
+          palcol[1], palcol[2], palcol[3] = colours.rgb8(r)
+      else
+          if type(r) ~= "number" then error("bad argument #2 (expected number, got " .. type(r) .. ")", 2) end
+          if type(g) ~= "number" then error("bad argument #3 (expected number, got " .. type(g) .. ")", 2) end
+          if type(b) ~= "number" then error("bad argument #4 (expected number, got " .. type(b) .. ")", 2) end
+
+          palcol[1], palcol[2], palcol[3] = r, g, b
+      end
+
+      if bubble then return original.setPaletteColour(colour, r, g, b) end
+    end
+    redirect.setPaletteColor = redirect.setPaletteColour
+
+    function redirect.getPaletteColour(colour)
+      if delegate then return delegate.getPaletteColour(colour) end
+
+      local palcol = palette[colour]
+      if not palcol then error("Invalid colour (got " .. tostring(colour) .. ")", 2) end
+      return palcol[1], palcol[2], palcol[3]
+    end
+    redirect.getPaletteColor = redirect.getPaletteColour
+  end
+
+  function redirect.draw(offset, clear)
+    if delegate then return end
+
+    if original.getPaletteColour then
+      for colour, pal in pairs(palette) do
+        original.setPaletteColour(colour, pal[1], pal[2], pal[3])
+      end
+    end
+
+    original.setTextColour(2 ^ tonumber(cur_text_colour, 16))
+    original.setBackgroundColor(2 ^ tonumber(cur_back_colour, 16))
+    if clear then original.clear() end
+
+    local original = original
+    local scroll_offset = scroll_offset + (offset or 0)
+    for i = 1, sizeY do
+      original.setCursorPos(1,i)
+      local yOffset = scroll_offset + i
+      original.blit(text[yOffset], text_colour[yOffset], back_colour[yOffset])
+    end
+
+    original.setCursorPos(cursor_x, cursor_y - offset)
+    original.setCursorBlink(cursor_blink)
+  end
+
+  function redirect.bubble(b)
+    bubble = b
+  end
+
+  function redirect.setCursorThreshold(y)
+    cursor_threshold = y
+  end
+
+  function redirect.endPrivateMode(redraw)
+    if delegate then
+      local old_delegate = delegate
+      delegate = nil
+      redirect.draw(0)
+
+      -- If we should redraw the old buffer then blit it to the canvas
+      if redraw then
+        if cursor_threshold > 0 then
+          redirect.scroll(cursor_threshold)
+        end
+
+        old_delegate.draw(redirect)
+      end
+    end
+  end
+
+  function redirect.beginPrivateMode()
+    if not delegate then
+      delegate = blit_window.create(original)
+
+      for y = 1, sizeY do
+        delegate.setCursorPos(1, y)
+        delegate.blit(text[y + scroll_offset], text_colour[y + scroll_offset], back_colour[y + scroll_offset])
+      end
+
+      delegate.setCursorPos(cursor_x, cursor_y)
+      delegate.setCursorBlink(cursor_blink)
+      delegate.setTextColour(2 ^ tonumber(cur_text_colour, 16))
+      delegate.setBackgroundColor(2 ^ tonumber(cur_back_colour, 16))
+
+      if original.getPaletteColour then
+        for i = 0, 15 do
+          local palcol = palette[2 ^ i]
+          delegate.setPaletteColour(2 ^ i, palcol[1], palcol[2], palcol[3])
+        end
+      end
+    end
+
+    return delegate
+  end
+
+  function redirect.isPrivateMode()
+    return delegate ~= nil
+  end
+
+  function redirect.getTotalHeight() return scroll_offset end
+
+  function redirect.setMaxScrollback(n)
+    local old_scrollback = max_scrollback
+    max_scrollback = n
+
+    if old_scrollback > max_scrollback then trim() end
+  end
+
+  function redirect.updateSize()
+    -- Update the delegate window.
+    if delegate then delegate.updateSize() end
+
+    -- If nothing has changed then just skip.
+    local new_x, new_y = original.getSize()
+    if new_x == sizeX and new_y == sizeY then return end
+
+    -- If we have an insufficient number of lines then add some in.
+    local total_height = #text
+
+    -- For any existing lines, trim them
+    for y = 1, total_height do
+      if new_x < sizeX then
+        text[y] = text[y]:sub(1, new_x)
+        text_colour[y] = text_colour[y]:sub(1, new_x)
+        back_colour[y] = back_colour[y]:sub(1, new_x)
+      elseif new_x > sizeX then
+        text[y] = text[y] .. (" "):rep(new_x - sizeX)
+        text_colour[y] = text_colour[y] .. (cur_text_colour):rep(new_x - sizeX)
+        back_colour[y] = back_colour[y] .. (cur_back_colour):rep(new_x - sizeX)
+      end
+    end
+
+    if new_y > sizeY then
+      -- Append any new lines we might need.
+      local text_line = (" "):rep(new_x)
+      local fore_line = (cur_text_colour):rep(new_x)
+      local back_line = (cur_back_colour):rep(new_x)
+      for y = total_height + 1, new_y do
+        text[y] = text_line
+        text_colour[y] = fore_line
+        back_colour[y] = back_line
+      end
+    elseif new_y < sizeY then
+      -- Move the cursor "up" the screen, as we're going to scroll the rest of
+      -- the terminal up.
+      -- Note, this is a little ugly (we lose the top of the screen even if we)
+      -- don't need to, but it's the best we can do for now.
+      cursor_y = cursor_y - sizeY + new_y
+    end
+
+    sizeX = new_x
+    sizeY = new_y
+
+    -- Update the scroll offset. For now we just go back to the bottom
+    scroll_offset = #text - sizeY
+    scroll_cursor_y = scroll_offset + cursor_y
+    trim()
+  end
+
+  redirect.clear()
+  return redirect
+end
\ No newline at end of file
diff --git a/.mbs/lib/stack_trace.lua b/.mbs/lib/stack_trace.lua
new file mode 100644
index 0000000..7674813
--- /dev/null
+++ b/.mbs/lib/stack_trace.lua
@@ -0,0 +1,88 @@
+local type = type
+local debug_traceback = type(debug) == "table" and type(debug.traceback) == "function" and debug.traceback
+
+local function traceback(x)
+  -- Attempt to detect error() and error("xyz", 0).
+  -- This probably means they're erroring the program intentionally and so we
+  -- shouldn't display anything.
+  if x == nil or (type(x) == "string" and not x:find(":%d+:")) then
+    return x
+  end
+
+  if debug_traceback then
+    -- The parens are important, as they prevent a tail call occuring, meaning
+    -- the stack level is preserved. This ensures the code behaves identically
+    -- on LuaJ and PUC Lua.
+    return (debug_traceback(tostring(x), 2))
+  else
+    local level = 3
+    local out = { tostring(x), "stack traceback:" }
+    while true do
+      local _, msg = pcall(error, "", level)
+      if msg == "" then break end
+
+      out[#out + 1] = "  " .. msg
+      level = level + 1
+    end
+
+    return table.concat(out, "\n")
+  end
+end
+
+local function trim_traceback(target, marker)
+  local ttarget, tmarker = {}, {}
+  for line in target:gmatch("([^\n]*)\n?") do ttarget[#ttarget + 1] = line end
+  for line in marker:gmatch("([^\n]*)\n?") do tmarker[#tmarker + 1] = line end
+
+  -- Trim identical suffixes
+  local t_len, m_len = #ttarget, #tmarker
+  while t_len >= 3 and ttarget[t_len] == tmarker[m_len] do
+    table.remove(ttarget, t_len)
+    t_len, m_len = t_len - 1, m_len - 1
+  end
+
+  -- Trim elements from this file and xpcall invocations
+  while t_len >= 1 and ttarget[t_len]:find("^\tstack_trace%.lua:%d+:") or
+        ttarget[t_len] == "\t[C]: in function 'xpcall'" or ttarget[t_len] == "  xpcall: " do
+    table.remove(ttarget, t_len)
+    t_len = t_len - 1
+  end
+
+  return ttarget
+end
+
+--- Run a function with
+local function xpcall_with(fn)
+  -- So this is rather grim: we need to get the full traceback and current one and remove
+  -- the common prefix
+  local trace
+  local res = table.pack(xpcall(fn, traceback)) if not res[1] then trace = traceback("trace.lua:1:") end
+  local ok, err = res[1], res[2]
+
+  if not ok and err ~= nil then
+    trace = trim_traceback(err, trace)
+
+    -- Find the position where the stack traceback actually starts
+    local trace_starts
+    for i = #trace, 1, -1 do
+      if trace[i] == "stack traceback:" then trace_starts = i; break end
+    end
+
+    -- If this traceback is more than 15 elements long, keep the first 9, last 5
+    -- and put an ellipsis between the rest
+    local max = 15
+    if trace_starts and #trace - trace_starts > max then
+      local keep_starts = trace_starts + 10
+      for i = #trace - trace_starts - max, 0, -1 do table.remove(trace, keep_starts + i) end
+      table.insert(trace, keep_starts, "  ...")
+    end
+
+    return false, table.concat(trace, "\n")
+  end
+
+  return table.unpack(res, 1, res.n)
+end
+
+_ENV.traceback = traceback
+_ENV.trim_traceback = trim_traceback
+_ENV.xpcall_with = xpcall_with
\ No newline at end of file
diff --git a/.mbs/modules/lua.lua b/.mbs/modules/lua.lua
new file mode 100644
index 0000000..d9453e6
--- /dev/null
+++ b/.mbs/modules/lua.lua
@@ -0,0 +1,58 @@
+local function lib_load(path, name)
+  if not _G[name] then
+    os.loadAPI(fs.combine(path, "lib/" .. name .. ".lua"))
+    if not _G[name] then _G[name] = _G[name .. ".lua"] end
+  end
+end
+
+return {
+  description = "Replaces the Lua REPL with an advanced version.",
+
+  dependencies = {
+    "bin/lua.lua",
+    "lib/stack_trace.lua"
+  },
+
+  -- When updating the defaults, one should also update bin/lua.lua
+  settings = {
+    {
+      name = "mbs.lua.enabled",
+      description = "Whether the extended Lua REPL is enabled.",
+      default = true,
+    },
+    {
+      name = "mbs.lua.history_file",
+      description = "The file to save history to. Set to false to disable.",
+      default = ".lua_history",
+    },
+    {
+      name = "mbs.lua.history_max",
+      description = "The maximum size of the history file",
+      default = 1e4,
+    },
+    {
+      name = "mbs.lua.traceback",
+      description = "Show an error traceback when an input errors",
+      default = true,
+    },
+    {
+      name= "mbs.lua.pretty_height",
+      description = "The height to fit the pretty-printer output to. Set to "
+        .. "false to disable, true to use the terminal height or a number for a constant height.",
+      default = true,
+    },
+    {
+      name= "mbs.lua.highlight",
+      description = "Whether to apply syntax highlighting to the REPL's input.",
+      default = true,
+    },
+  },
+
+  enabled = function() return settings.get("mbs.lua.enabled") end,
+
+  setup = function(path)
+    lib_load(path, "stack_trace")
+
+    shell.setAlias("lua", "/" .. fs.combine(path, "bin/lua.lua"))
+  end
+}
\ No newline at end of file
diff --git a/.mbs/modules/pager.lua b/.mbs/modules/pager.lua
new file mode 100644
index 0000000..7c25afb
--- /dev/null
+++ b/.mbs/modules/pager.lua
@@ -0,0 +1,48 @@
+return {
+  description = "Replaces the textutils pagers with something akin to less",
+
+  dependencies = {
+    "bin/help.lua"
+  },
+
+  settings = {
+    {
+      name = "mbs.pager.enabled",
+      description = "Whether the alternative pager is enabled.",
+      default = true,
+    },
+    {
+      name = "mbs.pager.mode",
+      description = "The mode for the alternative pager.",
+      default = "default",
+    }
+  },
+
+  enabled = function() return settings.get("mbs.pager.enabled") end,
+
+  setup = function(path)
+    shell.setAlias("help", "/" .. fs.combine(path, "bin/help.lua"))
+    shell.setCompletionFunction(fs.combine(path, "bin/help.lua"), function(shell, index, text, previous)
+      if index == 1 then return help.completeTopic(text) end
+    end)
+
+    local native_pprint, native_ptabulate = textutils.pagedPrint, textutils.pagedTabulate
+    textutils.pagedPrint = function(text, free_lines)
+      local mode = settings.get("mbs.pager.mode")
+      if mode == "none" then
+        return io.write(text .. "\n")
+      else
+        return native_pprint(text, free_lines)
+      end
+    end
+
+    textutils.pagedTabulate = function(...)
+      local mode = settings.get("mbs.pager.mode")
+      if mode == "none" then
+        return textutils.tabulate(...)
+      else
+        return native_ptabulate(...)
+      end
+    end
+  end
+}
\ No newline at end of file
diff --git a/.mbs/modules/readline.lua b/.mbs/modules/readline.lua
new file mode 100644
index 0000000..4dea9eb
--- /dev/null
+++ b/.mbs/modules/readline.lua
@@ -0,0 +1,66 @@
+--- Additional readline
+
+local function lib_load(path, name)
+  if not _G[name] then
+    os.loadAPI(fs.combine(path, "lib/" .. name .. ".lua"))
+    if not _G[name] then _G[name] = _G[name .. ".lua"] end
+  end
+end
+
+return {
+  description =
+    "This module extends the default read function, adding keybindings similar to " ..
+    "those provided by Emacs or GNU readline as well as additional configuration options.",
+
+  dependencies = {
+    "lib/readline.lua",
+  },
+
+  settings = {
+    {
+      name = "mbs.readline.enabled",
+      description = "Whether the readline module is enabled.",
+      default = true,
+    },
+    {
+      name = "mbs.readline.complete_bg",
+      description = "The background colour for completions.",
+      default = "none",
+    },
+    {
+      name = "mbs.readline.complete_fg",
+      description = "The foreground colour for completions.",
+      default = "grey",
+    }
+  },
+
+  enabled = function() return settings.get("mbs.readline.enabled") end,
+
+  setup = function(path)
+    lib_load(path, "readline")
+
+    -- Replace the default read function
+    _G.read = function(replace_char, history, complete, default)
+      if replace_char ~= nil and type(replace_char) ~= "string" then
+        error("bad argument #1 (expected string, got " .. type(replace_char) .. ")", 2)
+      end
+      if history ~= nil and type(history) ~= "table" then
+        error("bad argument #2 (expected table, got " .. type(history) .. ")", 2)
+      end
+      if complete ~= nil and type(complete) ~= "function" then
+        error("bad argument #3 (expected function, got " .. type(complete) .. ")", 2)
+      end
+      if default ~= nil and type(default) ~= "string" then
+        error("bad argument #4 (expected string, got " .. type(default) .. ")", 2)
+      end
+
+      return readline.read {
+        replace_char = replace_char,
+        history = history,
+        complete = complete,
+        default = default,
+      }
+    end
+
+  end,
+}
\ No newline at end of file
diff --git a/.mbs/modules/shell.lua b/.mbs/modules/shell.lua
new file mode 100644
index 0000000..035322d
--- /dev/null
+++ b/.mbs/modules/shell.lua
@@ -0,0 +1,81 @@
+local function lib_load(path, name)
+  if not _G[name] then
+    os.loadAPI(fs.combine(path, "lib/" .. name .. ".lua"))
+    if not _G[name] then _G[name] = _G[name .. ".lua"] end
+  end
+end
+
+return {
+  description = "Replaces the shell with an advanced version.",
+
+  dependencies = {
+    "bin/clear.lua",
+    "bin/shell.lua",
+    "lib/blit_window.lua",
+    "lib/scroll_window.lua",
+    "lib/stack_trace.lua",
+  },
+
+  -- When updating the defaults, one should also update bin/shell.lua
+  settings = {
+    {
+      name = "mbs.shell.enabled",
+      description = "Whether the extended shell is enabled.",
+      default = true,
+    },
+    {
+      name = "mbs.shell.history_file",
+      description = "The file to save history to. Set to false to disable.",
+      default = ".shell_history",
+    },
+    {
+      name = "mbs.shell.history_max",
+      description = "The maximum size of the history file",
+      default = 1e4,
+    },
+    {
+      name = "mbs.shell.scroll_max",
+      description = "The maximum size of the scrollback",
+      default = 1e3,
+    },
+    {
+      name = "mbs.shell.traceback",
+      description = "Show an error traceback when a program errors",
+      default = true,
+    },
+    {
+      name = "mbs.shell.require_path",
+      description = "The path from that require will use by default. Set to false to use the CraftOS default.",
+      default = false,
+    },
+    {
+      name = "mbs.shell.strict_globals",
+      description = "When set to true the shell will throw errors when programs attempt to define new globals in their environment. If you really want globals then you should use _G instead.",
+      default = false,
+    },
+  },
+
+  enabled = function() return settings.get("mbs.shell.enabled") end,
+
+  setup = function(path)
+    lib_load(path, "scroll_window")
+    lib_load(path, "blit_window")
+    lib_load(path, "stack_trace")
+
+    shell.setAlias("shell", "/" .. fs.combine(path, "bin/shell.lua"))
+    shell.setAlias("clear", "/" .. fs.combine(path, "bin/clear.lua"))
+
+    shell.setCompletionFunction(fs.combine(path, "bin/shell.lua"), function(shell, index, text, previous)
+      if index == 1 then return shell.completeProgram(text) end
+    end)
+  end,
+
+  startup = function(path)
+    local fn, err = loadfile(fs.combine(path, "bin/shell.lua"), _ENV)
+    if not fn then error(err) end
+
+    fn()
+
+    shell.exit()
+  end,
+}
\ No newline at end of file
diff --git a/README.md b/README.md
index bc0a5ea..ba508fd 100644
--- a/README.md
+++ b/README.md
@@ -12,6 +12,7 @@ The programs/apis I used for bits-UI.
 - FireWolf by GravityScore and 1lann
 - Mouse File Browser by Stiepen irc(Kilobyte), Cruor and BigSHinyToys
 - Enchat 3 by LDDestroier
+- Mildly Better Shell by SquidDev
 - fLib by NDFJay
 - Sha256 by Anavrins
 - JSON API by ElvishJerricco
diff --git a/boot/bubl.cfg b/boot/bubl.cfg
deleted file mode 100644
index 0c3582e..0000000
--- a/boot/bubl.cfg
+++ /dev/null
@@ -1,3 +0,0 @@
-{
-    "bitsui": "/system/boot.lua"
-}
\ No newline at end of file
diff --git a/startup b/startup
deleted file mode 100644
index 452ac9a..0000000
--- a/startup
+++ /dev/null
@@ -1 +0,0 @@
-shell.run("startup.lua") -- It redirects to the startup lua file if it's running a older version of CraftOS.
diff --git a/startup.lua b/startup.lua
index 424850e..8456680 100644
--- a/startup.lua
+++ b/startup.lua
@@ -34,7 +34,7 @@ function bootloader()
     term.setCursorPos(1,6)
     print("3. Recovery Mode\n")
     term.setCursorPos(1,7)
-    print("4. Boot CraftOS\n")
+    print("4. Boot CraftOS with MBS\n")
     term.setCursorPos(1,9)
     term.write("> ")
 end
@@ -84,8 +84,10 @@ function bootloaderInput()
         shell.run("/system/recovery/main.lua")
     elseif input == "4" then
         clear()
+        sleep(1)
+        assert(loadfile("/.mbs/bin/mbs.lua", _ENV))('startup')
         term.setTextColor(16)
-        print(os.version())
+        print(os.version() .. " (+MBS)")
         term.setCursorPos(1,2)
         term.setTextColor(1)
     else
@@ -99,22 +101,12 @@ function bootloaderInput()
 end
 clear()
 print("Welcome to BUBL!")
-if fs.exists(bublcfg) then
-    sleep(1)
-    if fs.exists("/.git") then
-        devMode = true
-        else
-        devMode = false
-        end
-    clear()
-    bootloader()
-    bootloaderInput()
+sleep(1)
+if fs.exists("/.git") then
+    devMode = true
 else
-    clear()
-    term.setTextColor(colors.red)
-    print("[ERROR] System cannot find bubl.cfg...")
-    term.setCursorPos(1,2)
-    print("System halted...")  
-    sleep(2)
-    os.shutdown()  
+    devMode = false
 end
+clear()
+bootloader()
+bootloaderInput()
\ No newline at end of file