diff --git a/sys/apis/ansi.lua b/sys/apis/ansi.lua
index 54b8227..b037e07 100644
--- a/sys/apis/ansi.lua
+++ b/sys/apis/ansi.lua
@@ -1,5 +1,5 @@
 local Ansi = setmetatable({ }, {
-  __call = function(self, ...)
+  __call = function(_, ...)
     local str = '\027['
     for k,v in ipairs({ ...}) do
       if k == 1 then
diff --git a/sys/apis/config.lua b/sys/apis/config.lua
index 4ebe0d3..ef0e91d 100644
--- a/sys/apis/config.lua
+++ b/sys/apis/config.lua
@@ -1,5 +1,7 @@
 local Util = require('util')
 
+local fs = _G.fs
+
 local Config = { }
 
 Config.load = function(fname, data)
diff --git a/sys/apis/event.lua b/sys/apis/event.lua
index dc09f86..41fab79 100644
--- a/sys/apis/event.lua
+++ b/sys/apis/event.lua
@@ -1,3 +1,5 @@
+local os = _G.os
+
 local Event = {
   uid       = 1,       -- unique id for handlers
   routines  = { },     -- coroutines
@@ -123,13 +125,13 @@ function Event.waitForEvent(event, timeout)
     local e = { os.pullEvent() }
     if e[1] == event then
       return table.unpack(e)
-    end 
+    end
   until e[1] == 'timer' and e[2] == timerId
 end
 
 function Event.addRoutine(fn)
   local r = {
-    co  = coroutine.create(fn), 
+    co  = coroutine.create(fn),
     uid = nextUID()
   }
   setmetatable(r, { __index = Routine })
diff --git a/sys/apis/fs/gitfs.lua b/sys/apis/fs/gitfs.lua
index b38388b..8b54d4a 100644
--- a/sys/apis/fs/gitfs.lua
+++ b/sys/apis/fs/gitfs.lua
@@ -1,5 +1,7 @@
 local git = require('git')
 
+local fs = _G.fs
+
 local gitfs = { }
 
 function gitfs.mount(dir, repo)
diff --git a/sys/apis/fs/linkfs.lua b/sys/apis/fs/linkfs.lua
index 86f0637..f497947 100644
--- a/sys/apis/fs/linkfs.lua
+++ b/sys/apis/fs/linkfs.lua
@@ -1,6 +1,8 @@
+local fs = _G.fs
+
 local linkfs = { }
 
-local methods = { 'exists', 'getFreeSpace', 'getSize', 
+local methods = { 'exists', 'getFreeSpace', 'getSize',
   'isDir', 'isReadOnly', 'list', 'listEx', 'makeDir', 'open', 'getDrive' }
 
 for _,m in pairs(methods) do
@@ -10,7 +12,7 @@ for _,m in pairs(methods) do
   end
 end
 
-function linkfs.mount(dir, source)
+function linkfs.mount(_, source)
   if not source then
     error('Source is required')
   end
@@ -23,7 +25,7 @@ function linkfs.mount(dir, source)
   end
   return {
     source = source
-  }  
+  }
 end
 
 function linkfs.copy(node, s, t)
diff --git a/sys/apis/fs/netfs.lua b/sys/apis/fs/netfs.lua
index 00fa0b6..c9f8253 100644
--- a/sys/apis/fs/netfs.lua
+++ b/sys/apis/fs/netfs.lua
@@ -1,11 +1,13 @@
-local Socket = require('socket')
+local Socket       = require('socket')
 local synchronized = require('sync')
 
+local fs = _G.fs
+
 local netfs = { }
 
 local function remoteCommand(node, msg)
 
-  for i = 1, 2 do
+  for _ = 1, 2 do
     if not node.socket then
       node.socket = Socket.connect(node.id, 139)
     end
@@ -49,7 +51,7 @@ for _,m in pairs(methods) do
   end
 end
 
-function netfs.mount(dir, id, directory)
+function netfs.mount(_, id, directory)
   if not id or not tonumber(id) then
     error('ramfs syntax: computerId [directory]')
   end
diff --git a/sys/apis/fs/ramfs.lua b/sys/apis/fs/ramfs.lua
index ee0c0f5..b4376c9 100644
--- a/sys/apis/fs/ramfs.lua
+++ b/sys/apis/fs/ramfs.lua
@@ -1,8 +1,10 @@
 local Util   = require('util')
 
+local fs = _G.fs
+
 local ramfs = { }
 
-function ramfs.mount(dir, nodeType)
+function ramfs.mount(_, nodeType)
   if nodeType == 'directory' then
     return {
       nodes = { },
@@ -34,7 +36,7 @@ function ramfs.isReadOnly()
   return false
 end
 
-function ramfs.makeDir(node, dir)
+function ramfs.makeDir(_, dir)
   fs.mount(dir, 'ramfs', 'directory')
 end
 
@@ -46,10 +48,10 @@ function ramfs.getDrive()
   return 'ram'
 end
 
-function ramfs.list(node, dir, full)
+function ramfs.list(node, dir)
   if node.nodes and node.mountPoint == dir then
     local files = { }
-    for k,v in pairs(node.nodes) do
+    for k in pairs(node.nodes) do
       table.insert(files, k)
     end
     return files
diff --git a/sys/apis/fs/urlfs.lua b/sys/apis/fs/urlfs.lua
index aecfd39..3ffd839 100644
--- a/sys/apis/fs/urlfs.lua
+++ b/sys/apis/fs/urlfs.lua
@@ -1,9 +1,11 @@
 local synchronized = require('sync')
 local Util         = require('util')
 
+local fs = _G.fs
+
 local urlfs = { }
 
-function urlfs.mount(dir, url)
+function urlfs.mount(_, url)
   if not url then
     error('URL is required')
   end
@@ -12,7 +14,7 @@ function urlfs.mount(dir, url)
   }
 end
 
-function urlfs.delete(node, dir)
+function urlfs.delete(_, dir)
   fs.unmount(dir)
 end
 
diff --git a/sys/apis/git.lua b/sys/apis/git.lua
index b6e95e4..6e8d9e1 100644
--- a/sys/apis/git.lua
+++ b/sys/apis/git.lua
@@ -6,9 +6,9 @@ local FILE_URL = 'https://raw.githubusercontent.com/%s/%s/%s/%s'
 
 local git = { }
 
-function git.list(repo)
+function git.list(repository)
 
-  local t = Util.split(repo, '(.-)/')
+  local t = Util.split(repository, '(.-)/')
 
   local user = t[1]
   local repo = t[2]
@@ -33,7 +33,7 @@ function git.list(repo)
 
   local list = { }
 
-  for k,v in pairs(data.tree) do
+  for _,v in pairs(data.tree) do
     if v.type == "blob" then
       v.path = v.path:gsub("%s","%%20")
       list[v.path] = {
diff --git a/sys/apis/gps.lua b/sys/apis/gps.lua
index 4abaafd..8d60d9e 100644
--- a/sys/apis/gps.lua
+++ b/sys/apis/gps.lua
@@ -1,5 +1,9 @@
 local GPS = { }
 
+local device = _G.device
+local gps    = _G.gps
+local turtle = _G.turtle
+
 function GPS.locate(timeout, debug)
   local pt = { }
   timeout = timeout or 10
@@ -14,7 +18,6 @@ function GPS.isAvailable()
 end
 
 function GPS.getPoint(timeout, debug)
- 
   local pt = GPS.locate(timeout, debug)
   if not pt then
     return
@@ -24,7 +27,7 @@ function GPS.getPoint(timeout, debug)
   pt.y = math.floor(pt.y)
   pt.z = math.floor(pt.z)
 
-  if pocket then
+  if _G.pocket then
     pt.y = pt.y - 1
   end
 
@@ -47,7 +50,7 @@ function GPS.getHeading(timeout)
   while not turtle.forward() do
     turtle.turnRight()
     if turtle.getHeading() == heading then
-      printError('GPS.getPoint: Unable to move forward')
+      _G.printError('GPS.getPoint: Unable to move forward')
       return
     end
   end
@@ -79,13 +82,13 @@ function GPS.getPointAndHeading(timeout)
 end
 
 -- from stock gps API
-local function trilaterate( A, B, C ) 
+local function trilaterate(A, B, C)
   local a2b = B.position - A.position
   local a2c = C.position - A.position
 
   if math.abs( a2b:normalize():dot( a2c:normalize() ) ) > 0.999 then
-    return nil 
-  end 
+    return
+  end
 
   local d = a2b:length()
   local ex = a2b:normalize( )
@@ -100,22 +103,22 @@ local function trilaterate( A, B, C )
 
   local x = (r1*r1 - r2*r2 + d*d) / (2*d)
   local y = (r1*r1 - r3*r3 - x*x + (x-i)*(x-i) + j*j) / (2*j)
- 
+
   local result = A.position + (ex * x) + (ey * y)
 
-  local zSquared = r1*r1 - x*x - y*y 
+  local zSquared = r1*r1 - x*x - y*y
   if zSquared > 0 then
     local z = math.sqrt( zSquared )
     local result1 = result + (ez * z)
     local result2 = result - (ez * z)
-    
+
     local rounded1, rounded2 = result1:round(), result2:round()
     if rounded1.x ~= rounded2.x or rounded1.y ~= rounded2.y or rounded1.z ~= rounded2.z then
       return rounded1, rounded2
     else
       return rounded1
-    end 
-  end 
+    end
+  end
   return result:round()
 end
 
@@ -129,7 +132,7 @@ local function narrow( p1, p2, fix )
     return p1:round()
   else
     return p2:round()
-  end 
+  end
 end
 -- end stock gps api
 
diff --git a/sys/apis/injector.lua b/sys/apis/injector.lua
index 5ad8e75..bd15e22 100644
--- a/sys/apis/injector.lua
+++ b/sys/apis/injector.lua
@@ -2,6 +2,10 @@ local DEFAULT_UPATH = 'https://raw.githubusercontent.com/kepler155c/opus/develop
 local PASTEBIN_URL  = 'http://pastebin.com/raw'
 local GIT_URL       = 'https://raw.githubusercontent.com'
 
+local fs   = _G.fs
+local http = _G.http
+local os   = _G.os
+
 -- fix broken http get
 local syncLocks = { }
 
@@ -44,7 +48,7 @@ end
 
 local function requireWrapper(env)
 
-  local function standardSearcher(modname, env, shell)
+  local function standardSearcher(modname)
     if package.loaded[modname] then
       return function()
         return package.loaded[modname]
@@ -52,18 +56,18 @@ local function requireWrapper(env)
     end
   end
 
-  local function shellSearcher(modname, env, shell)
+  local function shellSearcher(modname)
     local fname = modname:gsub('%.', '/') .. '.lua'
 
-    if shell and type(shell.dir) == 'function' then
-      local path = shell.resolve(fname)
+    if env.shell and type(env.shell.dir) == 'function' then
+      local path = env.shell.resolve(fname)
       if fs.exists(path) and not fs.isDir(path) then
         return loadfile(path, env)
       end
     end
   end
 
-  local function pathSearcher(modname, env, shell)
+  local function pathSearcher(modname)
     local fname = modname:gsub('%.', '/') .. '.lua'
 
     for dir in string.gmatch(package.path, "[^:]+") do
@@ -75,7 +79,7 @@ local function requireWrapper(env)
   end
 
   -- require('BniCQPVf')
-  local function pastebinSearcher(modname, env, shell)
+  local function pastebinSearcher(modname)
     if #modname == 8 and not modname:match('%W') then
       local url = PASTEBIN_URL .. '/' .. modname
       local c = loadUrl(url)
@@ -86,7 +90,7 @@ local function requireWrapper(env)
   end
 
   -- require('kepler155c.opus.master.sys.apis.util')
-  local function gitSearcher(modname, env, shell)
+  local function gitSearcher(modname)
     local fname = modname:gsub('%.', '/') .. '.lua'
     local _, count = fname:gsub("/", "")
     if count >= 3 then
@@ -98,7 +102,7 @@ local function requireWrapper(env)
     end
   end
 
-  local function urlSearcher(modname, env, shell)
+  local function urlSearcher(modname)
     local fname = modname:gsub('%.', '/') .. '.lua'
 
     if fname:sub(1, 1) ~= '/' then
@@ -113,7 +117,7 @@ local function requireWrapper(env)
   end
 
   -- place package and require function into env
-  package = {
+  env.package = {
     path = LUA_PATH or 'sys/apis',
     upath = LUA_UPATH or DEFAULT_UPATH,
     config = '/\n:\n?\n!\n-',
@@ -134,14 +138,14 @@ local function requireWrapper(env)
     }
   }
 
-  function require(modname)
+  function env.require(modname)
 
     for _,searcher in ipairs(package.loaders) do
-      local fn, msg = searcher(modname, env, shell)
+      local fn, msg = searcher(modname)
       if fn then
-        local module, msg = fn(modname, env)
+        local module, msg2 = fn(modname, env)
         if not module then
-          error(msg or (modname .. ' module returned nil'), 2)
+          error(msg2 or (modname .. ' module returned nil'), 2)
         end
         package.loaded[modname] = module
         return module
@@ -153,10 +157,11 @@ local function requireWrapper(env)
     error('Unable to find module ' .. modname)
   end
 
-  return require -- backwards compatible
+  return env.require -- backwards compatible
 end
 
 return function(env)
+  env = env or getfenv(2)
   setfenv(requireWrapper, env)
   return requireWrapper(env)
 end
diff --git a/sys/apis/json.lua b/sys/apis/json.lua
index e6c5fca..6fd5e37 100644
--- a/sys/apis/json.lua
+++ b/sys/apis/json.lua
@@ -189,7 +189,7 @@ function json.parseObject(str)
 
   local val = {}
   while str:sub(1, 1) ~= "}" do
-    local k, v = nil, nil
+    local k, v
     k, v, str = json.parseMember(str)
     val[k] = v
     str = removeWhite(str)
diff --git a/sys/apis/nft.lua b/sys/apis/nft.lua
index ee6ab7e..1bd1e70 100644
--- a/sys/apis/nft.lua
+++ b/sys/apis/nft.lua
@@ -21,7 +21,6 @@ function NFT.parse(imageText)
   }
 
   local num = 1
-  local index = 1
   for _,sLine in ipairs(Util.split(imageText)) do
     table.insert(image.fg, { })
     table.insert(image.bg, { })
@@ -47,7 +46,7 @@ function NFT.parse(imageText)
         fgNext = false
       else
         if nextChar ~= " " and currFG == nil then
-          currFG = colours.white
+          currFG = _G.colors.white
         end
         image.bg[num][writeIndex] = currBG
         image.fg[num][writeIndex] = currFG
diff --git a/sys/apis/opus.lua b/sys/apis/opus.lua
index 02e9b81..d37b918 100644
--- a/sys/apis/opus.lua
+++ b/sys/apis/opus.lua
@@ -1,3 +1,9 @@
+local colors = _G.colors
+local fs     = _G.fs
+local os     = _G.os
+--local shell  = _ENV.shell
+local term   = _G.term
+
 local Opus = { }
 
 local function runDir(directory, open)
@@ -27,7 +33,7 @@ local function runDir(directory, open)
       term.setTextColor(colors.white)
       term.write(fs.combine(directory, file))
       if err then
-        printError(err)
+        _G.printError(err)
       end
       success = false
     end
diff --git a/sys/apis/peripheral.lua b/sys/apis/peripheral.lua
index e2f372e..4b8178b 100644
--- a/sys/apis/peripheral.lua
+++ b/sys/apis/peripheral.lua
@@ -1,16 +1,14 @@
 local Util = require('util')
 
-local Peripheral = { }
-
-local function getDeviceList()
+local Peripheral = Util.shallowCopy(_G.peripheral)
 
+function Peripheral.getList()
   if _G.device then
     return _G.device
   end
 
   local deviceList = { }
-
-  for _,side in pairs(peripheral.getNames()) do
+  for _,side in pairs(Peripheral.getNames()) do
     Peripheral.addDevice(deviceList, side)
   end
 
@@ -19,14 +17,14 @@ end
 
 function Peripheral.addDevice(deviceList, side)
   local name = side
-  local ptype = peripheral.getType(side)
+  local ptype = Peripheral.getType(side)
 
   if not ptype then
     return
   end
 
   if ptype == 'modem' then
-    if peripheral.call(name, 'isWireless') then
+    if Peripheral.call(name, 'isWireless') then
       ptype = 'wireless_modem'
     else
       ptype = 'wired_modem'
@@ -52,10 +50,10 @@ function Peripheral.addDevice(deviceList, side)
     name = uniqueName
   end
 
-  local s, m pcall(function() deviceList[name] = peripheral.wrap(side) end)
+  local s, m = pcall(function() deviceList[name] = Peripheral.wrap(side) end)
   if not s and m then
-    printError('wrap failed')
-    printError(m)
+    _G.printError('wrap failed')
+    _G.printError(m)
   end
 
   if deviceList[name] then
@@ -70,15 +68,15 @@ function Peripheral.addDevice(deviceList, side)
 end
 
 function Peripheral.getBySide(side)
-  return Util.find(getDeviceList(), 'side', side)
+  return Util.find(Peripheral.getList(), 'side', side)
 end
 
 function Peripheral.getByType(typeName)
-  return Util.find(getDeviceList(), 'type', typeName)
+  return Util.find(Peripheral.getList(), 'type', typeName)
 end
 
 function Peripheral.getByMethod(method)
-  for _,p in pairs(getDeviceList()) do
+  for _,p in pairs(Peripheral.getList()) do
     if p[method] then
       return p
     end
@@ -92,8 +90,6 @@ function Peripheral.get(args)
     args = { type = args }
   end
 
-  args = args or { type = pType }
-
   if args.type then
     local p = Peripheral.getByType(args.type)
     if p then
diff --git a/sys/apis/point.lua b/sys/apis/point.lua
index cbdf461..3788738 100644
--- a/sys/apis/point.lua
+++ b/sys/apis/point.lua
@@ -37,7 +37,7 @@ end
 -- turtle distance (manhattan)
 function Point.turtleDistance(a, b)
   if a.y and b.y then
-    return math.abs(a.x - b.x) + 
+    return math.abs(a.x - b.x) +
            math.abs(a.y - b.y) +
            math.abs(a.z - b.z)
   else
@@ -116,7 +116,7 @@ function Point.calculateMoves(pta, ptb, distance)
       heading = ptb.heading
     end
   end
-  
+
   return moves, heading
 end
 
@@ -149,7 +149,7 @@ end
 function Point.adjacentPoints(pt)
   local pts = { }
 
-  for _, hi in pairs(turtle.getHeadings()) do
+  for _, hi in pairs(_G.turtle.getHeadings()) do
     table.insert(pts, { x = pt.x + hi.xd, y = pt.y + hi.yd, z = pt.z + hi.zd })
   end
 
diff --git a/sys/apis/security.lua b/sys/apis/security.lua
index 02e30e5..982ce98 100644
--- a/sys/apis/security.lua
+++ b/sys/apis/security.lua
@@ -28,7 +28,7 @@ function Security.getPublicKey()
   local function modexp(base, exponent, modulo)
     local remainder = base
 
-    for i = 1, exponent-1 do
+    for _ = 1, exponent-1 do
       remainder = remainder * remainder
       if remainder >= modulo then
         remainder = remainder % modulo
diff --git a/sys/apis/socket.lua b/sys/apis/socket.lua
index a087cef..4be73cf 100644
--- a/sys/apis/socket.lua
+++ b/sys/apis/socket.lua
@@ -3,6 +3,10 @@ local Logger   = require('logger')
 local Security = require('security')
 local Util     = require('util')
 
+local device    = _G.device
+local os        = _G.os
+local transport = _G.transport
+
 local socketClass = { }
 
 function socketClass:read(timeout)
@@ -165,7 +169,7 @@ function Socket.server(port)
   Logger.log('socket', 'Waiting for connections on port ' .. port)
 
   while true do
-    local e, _, sport, dport, msg = os.pullEvent('modem_message')
+    local _, _, sport, dport, msg = os.pullEvent('modem_message')
 
     if sport == port and
        msg and
diff --git a/sys/apis/sync.lua b/sys/apis/sync.lua
index 790ed4d..e0b841e 100644
--- a/sys/apis/sync.lua
+++ b/sys/apis/sync.lua
@@ -1,5 +1,7 @@
 local syncLocks = { }
 
+local os = _G.os
+
 return function(obj, fn)
   local key = tostring(obj)
   if syncLocks[key] then
diff --git a/sys/apis/terminal.lua b/sys/apis/terminal.lua
index af5bae3..5314d8e 100644
--- a/sys/apis/terminal.lua
+++ b/sys/apis/terminal.lua
@@ -1,14 +1,15 @@
 local Util = require('util')
 
+local colors = _G.colors
+local term   = _G.term
+local _gsub  = string.gsub
+
 local Terminal = { }
 
-local _sgsub = string.gsub
-
 function Terminal.scrollable(ct, size)
 
-  local size = size or 25
   local w, h = ct.getSize()
-  local win = window.create(ct, 1, 1, w, h + size, true)
+  local win = _G.window.create(ct, 1, 1, w, h + size, true)
   local oldWin = Util.shallowCopy(win)
   local scrollPos = 0
 
@@ -87,7 +88,7 @@ function Terminal.toGrayscale(ct)
   local methods = { 'setBackgroundColor', 'setBackgroundColour',
                     'setTextColor', 'setTextColour' }
   for _,v in pairs(methods) do
-  	local fn = ct[v]
+    local fn = ct[v]
     ct[v] = function(c)
       fn(scolors[c])
     end
@@ -110,7 +111,7 @@ function Terminal.toGrayscale(ct)
 
   local function translate(s)
     if s then
-      s = _sgsub(s, "%w", bcolors)
+      s = _gsub(s, "%w", bcolors)
     end
     return s
   end
@@ -136,9 +137,9 @@ end
 function Terminal.copy(it, ot)
   ot = ot or { }
   for k,v in pairs(it) do
-  	if type(v) == 'function' then
-  	  ot[k] = v
-  	end
+    if type(v) == 'function' then
+      ot[k] = v
+    end
   end
   return ot
 end
@@ -162,7 +163,7 @@ function Terminal.readPassword(prompt)
   local fn = term.current().write
   term.current().write = function() end
   local s
-  pcall(function() s = read(prompt) end)
+  pcall(function() s = _G.read(prompt) end)
   term.current().write = fn
 
   if s == '' then
diff --git a/sys/apis/turtle/pathfind.lua b/sys/apis/turtle/pathfind.lua
index b30744c..14cd9bf 100644
--- a/sys/apis/turtle/pathfind.lua
+++ b/sys/apis/turtle/pathfind.lua
@@ -1,19 +1,21 @@
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Grid       = require ("jumper.grid")
 local Pathfinder = require ("jumper.pathfinder")
 local Point      = require('point')
 local Util       = require('util')
 
+local turtle = _G.turtle
+
 local WALKABLE = 0
 
 local function createMap(dim)
 	local map = { }
-	for z = 1, dim.ez do
+	for _ = 1, dim.ez do
 		local row = {}
-		for x = 1, dim.ex do
+		for _ = 1, dim.ex do
 			local col = { }
-			for y = 1, dim.ey do
+			for _ = 1, dim.ey do
 				table.insert(col, WALKABLE)
 			end
 			table.insert(row, col)
@@ -80,10 +82,10 @@ local function mapDimensions(dest, blocks, boundingBox)
 
 	return {
 		ex = ex - sx + 1,
-		ez = ez - sz + 1, 
-		ey = ey - sy + 1, 
-		ox = -sx + 1, 
-		oz = -sz + 1, 
+		ez = ez - sz + 1,
+		ey = ey - sy + 1,
+		ox = -sx + 1,
+		oz = -sz + 1,
 		oy = -sy + 1
 	}
 end
@@ -149,7 +151,7 @@ local function selectDestination(pts, box, map, dim)
 			map[pt.z + dim.oz][pt.x + dim.ox][pt.y + dim.oy] == 1 then
 	    Util.removeByValue(pts, pt)
 	  else
-	  	return pt
+		return pt
 	  end
 	end
 end
@@ -169,7 +171,7 @@ local function pathTo(dest, options)
 	end
 
 	-- Creates a pathfinder object
-	local myFinder = Pathfinder(grid, 'ASTAR', walkable)
+	local myFinder = Pathfinder(grid, 'ASTAR', WALKABLE)
 
 	myFinder:setMode('ORTHOGONAL')
 	myFinder:setHeuristic(heuristic)
@@ -208,12 +210,14 @@ local function pathTo(dest, options)
 		local endPt = pointToMap(dim, dest)
 
 		-- Calculates the path, and its length
-		local path = myFinder:getPath(startPt.x, startPt.y, startPt.z, turtle.point.heading, endPt.x, endPt.y, endPt.z, dest.heading)
+		local path = myFinder:getPath(
+			startPt.x, startPt.y, startPt.z, turtle.point.heading,
+			endPt.x, endPt.y, endPt.z, dest.heading)
 
 		if not path then
 	    Util.removeByValue(dests, dest)
 		else
-			for node, count in path:nodes() do
+			for node in path:nodes() do
 				local pt = nodeToPoint(dim, node)
 
 				if turtle.abort then
@@ -223,10 +227,10 @@ local function pathTo(dest, options)
 				-- use single turn method so the turtle doesn't turn around
 				-- when encountering obstacles -- IS THIS RIGHT ??
 				if not turtle.gotoSingleTurn(pt.x, pt.z, pt.y, node.heading) then
-			  	table.insert(blocks, pt)
-			  	--if device.turtlesensorenvironment then
-			  	--	addSensorBlocks(blocks, device.turtlesensorenvironment.sonicScan())
-			  	--end
+					table.insert(blocks, pt)
+					--if device.turtlesensorenvironment then
+					--	addSensorBlocks(blocks, device.turtlesensorenvironment.sonicScan())
+					--end
 					break
 				end
 			end
diff --git a/sys/apis/ui.lua b/sys/apis/ui.lua
index e8a96c6..650a2fb 100644
--- a/sys/apis/ui.lua
+++ b/sys/apis/ui.lua
@@ -1320,7 +1320,7 @@ end
 function UI.Grid:adjustWidth()
 
   local t = { }        -- cols without width
-  local w = self.width - #self.columns - 1 - self.marginRight -- width remaing
+  local w = self.width - #self.columns - 1 - self.marginRight -- width remaining
 
   for _,c in pairs(self.columns) do
     if c.width then
diff --git a/sys/apis/ui/fileui.lua b/sys/apis/ui/fileui.lua
index 7bbd78f..d6d90d3 100644
--- a/sys/apis/ui/fileui.lua
+++ b/sys/apis/ui/fileui.lua
@@ -1,6 +1,9 @@
 local UI   = require('ui')
 local Util = require('util')
 
+local colors = _G.colors
+local fs     = _G.fs
+
 return function(args)
 
   local columns = {
@@ -86,7 +89,7 @@ return function(args)
     return row
   end
 
-  function selectFile.grid:getRowTextColor(file, selected)
+  function selectFile.grid:getRowTextColor(file)
     if file.isDir then
       return colors.cyan
     end
diff --git a/sys/apis/util.lua b/sys/apis/util.lua
index 4e51540..fda9ff0 100644
--- a/sys/apis/util.lua
+++ b/sys/apis/util.lua
@@ -162,7 +162,7 @@ end
 
 function Util.findAll(t, name, value)
   local rt = { }
-  for k,v in pairs(t) do
+  for _,v in pairs(t) do
     if v[name] == value then
       table.insert(rt, v)
     end
@@ -253,7 +253,7 @@ function Util.spairs(t, order)
   local keys = Util.keys(t)
 
   -- if order function given, sort by it by passing the table and keys a, b,
-  -- otherwise just sort the keys 
+  -- otherwise just sort the keys
   if order then
     table.sort(keys, function(a,b) return order(t[a], t[b]) end)
   else
@@ -317,7 +317,7 @@ function Util.writeLines(fname, lines)
   local file = fs.open(fname, 'w')
   if file then
     for _,line in ipairs(lines) do
-      line = file.writeLine(line)
+      file.writeLine(line)
     end
     file.close()
     return true
@@ -458,12 +458,12 @@ end
 function Util.trim(s)
   return s:find'^%s*$' and '' or s:match'^%s*(.*%S)'
 end
- 
+
 -- trim whitespace from left end of string
 function Util.triml(s)
   return s:match'^%s*(.*)'
 end
- 
+
 -- trim whitespace from right end of string
 function Util.trimr(s)
   return s:find'^%s*$' and '' or s:match'^(.*%S)'
@@ -548,7 +548,7 @@ end
 
 function Util.showOptions(options)
   print('Arguments: ')
-  for k, v in pairs(options) do
+  for _, v in pairs(options) do
     print(string.format('-%s  %s', v.arg, v.desc))
   end
 end
@@ -561,7 +561,6 @@ function Util.getOptions(options, args, ignoreInvalid)
     end
   end
   local rawOptions = getopt(args, argLetters)
-  local argCount = 0
 
   for k,ro in pairs(rawOptions) do
     local found = false
diff --git a/sys/apps/Files.lua b/sys/apps/Files.lua
index dd052a6..114f441 100644
--- a/sys/apps/Files.lua
+++ b/sys/apps/Files.lua
@@ -1,11 +1,15 @@
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Config = require('config')
 local Event  = require('event')
 local UI     = require('ui')
 local Util   = require('util')
 
-local colors = _G.colors
+local colors     = _G.colors
+local fs         = _G.fs
+local multishell = _ENV.multishell
+local os         = _G.os
+local shell      = _ENV.shell
 
 multishell.setTitle(multishell.getCurrent(), 'Files')
 UI:configure('Files', ...)
@@ -158,7 +162,7 @@ function Browser:setStatus(status, ...)
 end
 
 function Browser:unmarkAll()
-  for k,m in pairs(marked) do
+  for _,m in pairs(marked) do
     m.marked = false
   end
   Util.clear(marked)
@@ -198,7 +202,6 @@ function Browser:updateDirectory(dir)
     dir.size = #files
     for _, file in pairs(files) do
       file.fullName = fs.combine(dir.name, file.name)
-      file.directory = directory
       file.flags = ''
       if not file.isDir then
         dir.totalSize = dir.totalSize + file.size
@@ -232,7 +235,7 @@ function Browser:setDir(dirName, noStatus)
   if self.dir then
     self.dir.index = self.grid:getIndex()
   end
-  DIR = fs.combine('', dirName)
+  local DIR = fs.combine('', dirName)
   shell.setDir(DIR)
   local s, dir = self:getDirectory(DIR)
   if s then
diff --git a/sys/apps/Help.lua b/sys/apps/Help.lua
index 023b062..f585f0e 100644
--- a/sys/apps/Help.lua
+++ b/sys/apps/Help.lua
@@ -1,4 +1,4 @@
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local UI    = require('ui')
 local Util  = require('util')
diff --git a/sys/apps/Lua.lua b/sys/apps/Lua.lua
index 1c789ad..ceda415 100644
--- a/sys/apps/Lua.lua
+++ b/sys/apps/Lua.lua
@@ -1,15 +1,18 @@
-requireInjector = requireInjector or load(http.get('https://raw.githubusercontent.com/kepler155c/opus/master/sys/apis/injector.lua').readAll())()
-requireInjector(getfenv(1))
+local injector = _G.requireInjector or load(http.get('https://raw.githubusercontent.com/kepler155c/opus/master/sys/apis/injector.lua').readAll())()
+injector()
 
-local Event   = require('event')
-local History = require('history')
-local UI      = require('ui')
-local Util    = require('util')
+local Event      = require('event')
+local History    = require('history')
+local Peripheral = require('peripheral')
+local UI         = require('ui')
+local Util       = require('util')
 
-local sandboxEnv = setmetatable(Util.shallowCopy(getfenv(1)), { __index = _G })
+local multishell = _ENV.multishell
+
+local sandboxEnv = setmetatable(Util.shallowCopy(_ENV), { __index = _G })
 sandboxEnv.exit = function() Event.exitPullEvents() end
 sandboxEnv._echo = function( ... ) return ... end
-requireInjector(sandboxEnv)
+injector(sandboxEnv)
 
 multishell.setTitle(multishell.getCurrent(), 'Lua')
 UI:configure('Lua', ...)
@@ -112,12 +115,12 @@ function page:eventHandler(event)
 
   if event.type == 'global' then
     self:setPrompt('', true)
-    self:executeStatement('getfenv(0)')
+    self:executeStatement('_G')
     command = nil
 
   elseif event.type == 'local' then
     self:setPrompt('', true)
-    self:executeStatement('getfenv(1)')
+    self:executeStatement('_ENV')
     command = nil
 
   elseif event.type == 'autocomplete' then
@@ -129,11 +132,7 @@ function page:eventHandler(event)
 
   elseif event.type == 'device' then
     if not _G.device then
-      sandboxEnv.device = { }
-      for _,side in pairs(peripheral.getNames()) do
-        local key = string.format('%s:%s', peripheral.getType(side), side)
-        sandboxEnv.device[ key ] = peripheral.wrap(side)
-      end
+      sandboxEnv.device = Peripheral.getList()
     end
     self:setPrompt('device', true)
     self:executeStatement('device')
@@ -187,8 +186,7 @@ function page:setResult(result)
   local t = { }
 
   local function safeValue(v)
-    local t = type(v)
-    if t == 'string' or t == 'number' then
+    if type(v) == 'string' or type(v) == 'number' then
       return v
     end
     return tostring(v)
@@ -205,7 +203,7 @@ function page:setResult(result)
       if type(v) == 'table' then
         if Util.size(v) == 0 then
           entry.value = 'table: (empty)'
-        else 
+        else
           entry.value = 'table'
         end
       end
@@ -243,7 +241,7 @@ function page.grid:eventHandler(event)
       if type(entry.rawName) == 'number' then
         return command .. '[' .. entry.name .. ']'
       end
-      if entry.name:match("%W") or 
+      if entry.name:match("%W") or
          entry.name:sub(1, 1):match("%d") then
         return command .. "['" .. tostring(entry.name) .. "']"
       end
diff --git a/sys/apps/Network.lua b/sys/apps/Network.lua
index 02e3ee2..cb20acd 100644
--- a/sys/apps/Network.lua
+++ b/sys/apps/Network.lua
@@ -1,10 +1,16 @@
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Event  = require('event')
 local Socket = require('socket')
 local UI     = require('ui')
 local Util   = require('util')
 
+local colors     = _G.colors
+local device     = _G.device
+local multishell = _ENV.multishell
+local network    = _G.network
+local shell      = _ENV.shell
+
 multishell.setTitle(multishell.getCurrent(), 'Network')
 UI:configure('Network', ...)
 
@@ -124,14 +130,14 @@ Event.onInterval(1, function()
   page:sync()
 end)
 
-Event.on('device_attach', function(h, deviceName)
+Event.on('device_attach', function(_, deviceName)
   if deviceName == 'wireless_modem' then
     page.notification:success('Modem connected')
     page:sync()
   end
 end)
 
-Event.on('device_detach', function(h, deviceName)
+Event.on('device_detach', function(_, deviceName)
   if deviceName == 'wireless_modem' then
     page.notification:error('Wireless modem not attached')
     page:sync()
diff --git a/sys/apps/Overview.lua b/sys/apps/Overview.lua
index 099cd71..4d566bf 100644
--- a/sys/apps/Overview.lua
+++ b/sys/apps/Overview.lua
@@ -1,4 +1,4 @@
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local class  = require('class')
 local Config = require('config')
@@ -10,19 +10,13 @@ local Tween  = require('ui.tween')
 local UI     = require('ui')
 local Util   = require('util')
 
-local REGISTRY_DIR = 'usr/.registry'
-local TEMPLATE = [[
-local env = { }
-for k,v in pairs(getfenv(1)) do
-  env[k] = v 
-end
-setmetatable(env, { __index = _G })
+local fs         = _G.fs
+local multishell = _ENV.multishell
+local pocket     = _G.pocket
+local term       = _G.term
+local turtle     = _G.turtle
 
-local s, m = os.run(env, 'sys/apps/appRun.lua',  %s, ...)
-if not s then
-  error(m)
-end
-]]
+local REGISTRY_DIR = 'usr/.registry'
 
 multishell.setTitle(multishell.getCurrent(), 'Overview')
 UI:configure('Overview', ...)
@@ -93,13 +87,14 @@ end
 
 local buttons = { }
 local categories = { }
-table.insert(buttons, { text = 'Recent', event = 'category' })
 for _,f in pairs(applications) do
   if not categories[f.category] then
     categories[f.category] = true
     table.insert(buttons, { text = f.category, event = 'category' })
   end
 end
+table.sort(buttons, function(a, b) return a.text < b.text end)
+table.insert(buttons, 1, { text = 'Recent', event = 'category' })
 table.insert(buttons, { text = '+', event = 'new' })
 
 local function parseIcon(iconText)
@@ -159,17 +154,11 @@ local page = UI.Page {
     f = 'files',
     s = 'shell',
     l = 'lua',
-    [ 'control-l' ] = 'refresh',
     [ 'control-n' ] = 'new',
     delete = 'delete',
   },
 }
 
-function page:draw()
-  self.tabBar:draw()
-  self.container:draw()
-end
-
 UI.Icon = class(UI.Window)
 function UI.Icon:init(args)
   local defaults = {
@@ -194,7 +183,7 @@ function UI.Icon:eventHandler(event)
   return UI.Window.eventHandler(self, event)
 end
 
-function page.container:setCategory(categoryName)
+function page.container:setCategory(categoryName, animate)
 
   -- reset the viewport window
   self.children = { }
@@ -223,7 +212,7 @@ function page.container:setCategory(categoryName)
     end
 
   else
-    filtered = filter(applications, function(a) 
+    filtered = filter(applications, function(a)
       return a.category == categoryName -- and fs.exists(a.run)
     end)
     table.sort(filtered, function(a, b) return a.title < b.title end)
@@ -295,6 +284,11 @@ function page.container:setCategory(categoryName)
     end
     child.tween = Tween.new(6, child, { x = col, y = row }, 'linear')
 
+    if not animate then
+      child.x = col
+      child.y = row
+    end
+
     if k < count then
       col = col + child.width
       if col + self.children[k + 1].width + gutter - 2 > self.width then
@@ -305,32 +299,30 @@ function page.container:setCategory(categoryName)
   end
 
   self:initChildren()
-  local function transition(args)
-    local i = 1
-    return function(device)
-      self:clear()
-      for _,child in pairs(self.children) do
-        child.tween:update(1)
-        child.x = math.floor(child.x)
-        child.y = math.floor(child.y)
-        child:draw()
+  if animate then                      -- need to fix transitions under layers
+    local function transition(args)
+      local i = 1
+      return function(device)
+        self:clear()
+        for _,child in pairs(self.children) do
+          child.tween:update(1)
+          child.x = math.floor(child.x)
+          child.y = math.floor(child.y)
+          child:draw()
+        end
+        args.canvas:blit(device, args, args)
+        i = i + 1
+        return i < 7
       end
-      args.canvas:blit(device, args, args)
-      i = i + 1
-      return i < 7
     end
+    self:addTransition(transition)
   end
-  self:addTransition(transition)
-end
-
-function page.container:draw()
-  UI.Viewport.draw(self)
 end
 
 function page:refresh()
   local pos = self.container.offy
   self:focusFirst(self)
-  self.container:setCategory(config.currentCategory)    
+  self.container:setCategory(config.currentCategory)
   self.container:setScrollPosition(pos)
 end
 
@@ -343,9 +335,8 @@ function page:eventHandler(event)
 
   if event.type == 'category' then
     self.tabBar:selectTab(event.button.text)
-    self.container:setCategory(event.button.text)
+    self.container:setCategory(event.button.text, true)
     self.container:draw()
-    self:sync()
 
     config.currentCategory = event.button.text
     Config.update('Overview', config)
@@ -392,14 +383,7 @@ function page:eventHandler(event)
       event.focused.parent:scrollIntoView()
     end
 
-  elseif event.type == 'tab_change' then
-    if event.current > event.last then
-      --self.container:setTransition(UI.effect.slideLeft)
-    else
-      --self.container:setTransition(UI.effect.slideRight)
-    end
-
-  elseif event.type == 'refresh' then
+  elseif event.type == 'refresh' then -- remove this after fixing notification
     loadApplications()
     self:refresh()
     self:draw()
@@ -458,7 +442,7 @@ local editor = UI.Dialog {
       required = true,
     },
     loadIcon = UI.Button {
-      x = 11, y = 6, 
+      x = 11, y = 6,
       text = 'Icon', event = 'loadIcon', help = 'Select icon'
     },
     image = UI.NftImage {
@@ -569,5 +553,4 @@ page.tabBar:selectTab(config.currentCategory or 'Apps')
 page.container:setCategory(config.currentCategory or 'Apps')
 UI:setPage(page)
 
-Event.pullEvents()
-UI.term:reset()
+UI:pullEvents()
diff --git a/sys/apps/System.lua b/sys/apps/System.lua
index 6d79511..33a48eb 100644
--- a/sys/apps/System.lua
+++ b/sys/apps/System.lua
@@ -1,10 +1,14 @@
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Config = require('config')
-local Event  = require('event')
 local UI     = require('ui')
 local Util   = require('util')
 
+local fs         = _G.fs
+local multishell = _ENV.multishell
+local os         = _G.os
+local shell      = _ENV.shell
+
 multishell.setTitle(multishell.getCurrent(), 'System')
 UI:configure('System', ...)
 
@@ -30,7 +34,6 @@ local systemPage = UI.Page {
       },
       grid = UI.Grid {
         y = 4,
-        values = paths,
         disableHeader = true,
         columns = { { key = 'value' } },
         autospace = true,
@@ -40,7 +43,7 @@ local systemPage = UI.Page {
     aliasTab = UI.Window {
       tabTitle = 'Aliases',
       alias = UI.TextEntry {
-        x = 2, y = 2, ex = -2, 
+        x = 2, y = 2, ex = -2,
         limit = 32,
         shadowText = 'Alias',
       },
@@ -54,7 +57,6 @@ local systemPage = UI.Page {
       },
       grid = UI.Grid {
         y = 5,
-        values = aliases,
         autospace = true,
         sortColumn = 'alias',
         columns = {
@@ -87,7 +89,7 @@ local systemPage = UI.Page {
           { name = '',  value = ''                  },
           { name = 'CC version',  value = Util.getVersion()                  },
           { name = 'Lua version', value = _VERSION                           },
-          { name = 'MC version',  value = _MC_VERSION or 'unknown'           },
+          { name = 'MC version',  value = _G._MC_VERSION or 'unknown'        },
           { name = 'Disk free',   value = Util.toBytes(fs.getFreeSpace('/')) },
           { name = 'Computer ID', value = tostring(os.getComputerID())       },
           { name = 'Day',         value = tostring(os.day())                 },
@@ -129,7 +131,6 @@ end
 
 function systemPage.tabs.aliasTab.grid:draw()
   self.values = { }
-  local aliases = { }
   for k,v in pairs(env.aliases) do
     table.insert(self.values, { alias = k, path = v })
   end
@@ -170,7 +171,7 @@ end
 function systemPage:eventHandler(event)
 
   if event.type == 'quit' then
-    Event.exitPullEvents()
+    UI:exitPullEvents()
   elseif event.type == 'tab_activate' then
     event.activated:focusFirst()
   else
@@ -180,5 +181,4 @@ function systemPage:eventHandler(event)
 end
 
 UI:setPage(systemPage)
-Event.pullEvents()
-UI.term:reset()
+UI:pullEvents()
diff --git a/sys/apps/Tabs.lua b/sys/apps/Tabs.lua
index d22202f..b0de4c4 100644
--- a/sys/apps/Tabs.lua
+++ b/sys/apps/Tabs.lua
@@ -1,9 +1,11 @@
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Event = require('event')
 local UI    = require('ui')
 local Util  = require('util')
 
+local multishell = _ENV.multishell
+
 multishell.setTitle(multishell.getCurrent(), 'Tabs')
 UI:configure('Tabs', ...)
 
diff --git a/sys/apps/multishell b/sys/apps/multishell
index 6575239..b9ddfb5 100644
--- a/sys/apps/multishell
+++ b/sys/apps/multishell
@@ -1,31 +1,22 @@
--- Default label
-if not os.getComputerLabel() then
-  local id = os.getComputerID()
-  if turtle then
-    os.setComputerLabel('turtle_' .. id)
-  elseif pocket then
-    os.setComputerLabel('pocket_' .. id)
-  elseif commands then
-    os.setComputerLabel('command_' .. id)
-  else
-    os.setComputerLabel('computer_' .. id)
-  end
-end
-
-multishell.term = term.current()
-
 local defaultEnv = { }
-for k,v in pairs(getfenv(1)) do
-  defaultEnv[k] = v 
+for k,v in pairs(_ENV) do
+  defaultEnv[k] = v
 end
 
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Config = require('config')
 local Opus   = require('opus')
 local Util   = require('util')
 
-local SESSION_FILE = 'usr/config/multishell.session'
+local colors     = _G.colors
+local fs         = _G.fs
+local keys       = _G.keys
+local multishell = _ENV.multishell
+local os         = _G.os
+local printError = _G.printError
+local term       = _G.term
+local window     = _G.window
 
 local parentTerm = term.current()
 local w,h = parentTerm.getSize()
@@ -37,6 +28,22 @@ local runningTab
 local tabsDirty = false
 local closeInd = '*'
 
+multishell.term = term.current()
+
+-- Default label
+if not os.getComputerLabel() then
+  local id = os.getComputerID()
+  if _G.turtle then
+    os.setComputerLabel('turtle_' .. id)
+  elseif _G.pocket then
+    os.setComputerLabel('pocket_' .. id)
+  elseif _G.commands then
+    os.setComputerLabel('command_' .. id)
+  else
+    os.setComputerLabel('computer_' .. id)
+  end
+end
+
 if Util.getVersion() >= 1.79 then
   closeInd = '\215'
 end
@@ -59,7 +66,6 @@ local config = {
     focusBackgroundColor = colors.gray,
   },
 }
-
 Config.load('multishell', config)
 
 local _colors = config.standard
@@ -229,7 +235,6 @@ local function launchProcess(tab)
       selectTab(previousTab)
     end
     redrawMenu()
-    saveSession()
   end)
 
   tabs[tab.tabId] = tab
@@ -243,8 +248,7 @@ local function resizeWindows()
   local windowY = 2
   local windowHeight = h-1
 
-  local keys = Util.keys(tabs)
-  for _,key in pairs(keys) do
+  for _,key in pairs(Util.keys(tabs)) do
     local tab = tabs[key]
     local x,y = tab.window.getCursorPos()
     if y > windowHeight then
@@ -255,25 +259,11 @@ local function resizeWindows()
   end
 
   -- Pass term_resize to all processes
-  local keys = Util.keys(tabs)
-  for _,key in pairs(keys) do
+  for _,key in pairs(Util.keys(tabs)) do
     resumeTab(tabs[key], "term_resize")
   end
 end
 
-local function saveSession()
-  local t = { }
-  for _,process in pairs(tabs) do
-    if process.path and not process.isOverview and not process.hidden then
-      table.insert(t, {
-        path = process.path,
-        args = process.args,
-      })
-    end
-  end
-  --Util.writeTable(SESSION_FILE, t)
-end
-
 local control
 local hotkeys = { }
 
@@ -348,7 +338,6 @@ function multishell.terminate(tabId)
   local tab = tabs[tabId]
   if tab and not tab.isOverview then
     if coroutine.status(tab.co) ~= 'dead' then
-      --os.queueEvent('multishell', 'terminate', tab)
       resumeTab(tab, "terminate")
     else
       tabs[tabId] = nil
@@ -399,10 +388,6 @@ function multishell.openTab(tab)
     redrawMenu()
   end
 
-  if not tab.hidden then
-    saveSession()
-  end
-
   return tab.tabId
 end
 
@@ -423,11 +408,7 @@ function multishell.unhideTab(tabId)
 end
 
 function multishell.getCount()
-  local count
-  for _,tab in pairs(tabs) do
-    count = count + 1
-  end
-  return count
+  return Util.size(tabs)
 end
 
 -- control-o - overview
@@ -435,6 +416,10 @@ multishell.addHotkey(24, function()
   multishell.setFocus(overviewTab.tabId)
 end)
 
+multishell.addHotkey(20, function()
+  clipboard.useInternal(not clipboard.isInternal())
+end)
+
 -- control-backspace
 multishell.addHotkey(14, function()
   local tabId = multishell.getFocus()
@@ -474,7 +459,6 @@ end)
 
 local function startup()
   local hasError
-  local session = Util.readTable(SESSION_FILE)
 
   if not Opus.loadServices() then
     hasError = true
@@ -492,12 +476,6 @@ local function startup()
     hasError = true
   end
 
-  if session then
-    for _,v in pairs(session) do
-      --multishell.openTab(v)
-    end
-  end
-
   if hasError then
     print()
     error('An autorun program has errored')
@@ -514,10 +492,6 @@ multishell.openTab({
   title = 'Autorun',
 })
 
-if not overviewTab or coroutine.status(overviewTab.co) == 'dead' then
-  --error('Overview aborted')
-end
-
 if not currentTab then
   multishell.setFocus(overviewTab.tabId)
 end
@@ -562,13 +536,12 @@ while true do
 
     -- Keyboard event - Passthrough to current process
     resumeTab(currentTab, sEvent, tEventData)
-  
+
   elseif sEvent == "mouse_click" then
     local button, x, y = tEventData[1], tEventData[2], tEventData[3]
     lastClicked = nil
     if y == 1 then
       -- Switch process
-      local w, h = parentTerm.getSize()
       if x == 1 then
         multishell.setFocus(overviewTab.tabId)
       elseif x == w then
@@ -616,8 +589,7 @@ while true do
   else
     -- Other event
     -- Passthrough to all processes
-    local keys = Util.keys(tabs)
-    for _,key in pairs(keys) do
+    for _,key in pairs(Util.keys(tabs)) do
       resumeTab(tabs[key], sEvent, tEventData)
     end
   end
diff --git a/sys/apps/password.lua b/sys/apps/password.lua
index f82c22d..f6f3ef1 100644
--- a/sys/apps/password.lua
+++ b/sys/apps/password.lua
@@ -1,4 +1,4 @@
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Security = require('security')
 local SHA1     = require('sha1')
diff --git a/sys/apps/telnet.lua b/sys/apps/telnet.lua
index 06ce5f7..ce83d3a 100644
--- a/sys/apps/telnet.lua
+++ b/sys/apps/telnet.lua
@@ -1,10 +1,14 @@
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Event    = require('event')
 local Socket   = require('socket')
 local Terminal = require('terminal')
 local Util     = require('util')
 
+local os   = _G.os
+local read = _G.read
+local term = _G.term
+
 local remoteId
 local args = { ... }
 if #args == 1 then
diff --git a/sys/apps/trust.lua b/sys/apps/trust.lua
index eb67be6..946ff4d 100644
--- a/sys/apps/trust.lua
+++ b/sys/apps/trust.lua
@@ -1,4 +1,4 @@
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Crypto   = require('crypto')
 local Security = require('security')
@@ -6,6 +6,8 @@ local SHA1     = require('sha1')
 local Socket   = require('socket')
 local Terminal = require('terminal')
 
+local os = _G.os
+
 local remoteId
 local args = { ... }
 
@@ -13,7 +15,7 @@ if #args == 1 then
   remoteId = tonumber(args[1])
 else
   print('Enter host ID')
-  remoteId = tonumber(read())
+  remoteId = tonumber(_G.read())
 end
 
 if not remoteId then
@@ -34,9 +36,8 @@ if not socket then
 end
 
 local publicKey = Security.getPublicKey()
-local password = SHA1.sha1(password)
 
-socket:write(Crypto.encrypt({ pk = publicKey, dh = os.getComputerID() }, password))
+socket:write(Crypto.encrypt({ pk = publicKey, dh = os.getComputerID() }, SHA1.sha1(password)))
 
 local data = socket:read(2)
 socket:close()
diff --git a/sys/apps/vnc.lua b/sys/apps/vnc.lua
index b1f1ee9..2c00df1 100644
--- a/sys/apps/vnc.lua
+++ b/sys/apps/vnc.lua
@@ -1,17 +1,21 @@
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Event    = require('event')
 local Socket   = require('socket')
 local Terminal = require('terminal')
 local Util     = require('util')
 
+local colors     = _G.colors
+local multishell = _ENV.multishell
+local term       = _G.term
+
 local remoteId
 local args = { ... }
 if #args == 1 then
   remoteId = tonumber(args[1])
 else
   print('Enter host ID')
-  remoteId = tonumber(read())
+  remoteId = tonumber(_G.read())
 end
 
 if not remoteId then
@@ -73,7 +77,7 @@ while true do
     print()
     print('Connection lost')
     print('Press enter to exit')
-    read()
+    _G.read()
     break
   end
 
diff --git a/sys/boot/multishell.boot b/sys/boot/multishell.boot
index e7b7de5..ce2db5d 100644
--- a/sys/boot/multishell.boot
+++ b/sys/boot/multishell.boot
@@ -33,7 +33,7 @@ local BASE     = 'https://raw.githubusercontent.com/' .. GIT_REPO
 
 local function makeEnv()
   local env = setmetatable({ }, { __index = _G })
-  for k,v in pairs(getfenv(1)) do
+  for k,v in pairs(_ENV) do
     env[k] = v 
   end
   return env
@@ -53,7 +53,7 @@ local function runUrl(file, ...)
 
   local h = http.get(url)
   if h then
-    local fn, m = load(h.readAll(), url, nil, makeEnv())
+    local fn = load(h.readAll(), url, nil, makeEnv())
     h.close()
     if fn then
       return fn(...)
diff --git a/sys/extensions/clipboard.lua b/sys/extensions/clipboard.lua
index c63c509..e2ff628 100644
--- a/sys/extensions/clipboard.lua
+++ b/sys/extensions/clipboard.lua
@@ -2,11 +2,11 @@ if _G.clipboard then
   return
 end
 
-requireInjector(getfenv(1))
-
+_G.requireInjector()
 local Util = require('util')
+local os   = _G.os
 
-_G.clipboard = { internal, data }
+local clipboard = { }
 
 function clipboard.getData()
   return clipboard.data
@@ -36,8 +36,4 @@ function clipboard.useInternal(mode)
   end
 end
 
-if multishell and multishell.addHotkey then
-  multishell.addHotkey(20, function()
-    clipboard.useInternal(not clipboard.isInternal())
-  end)
-end
+_G.clipboard = clipboard
diff --git a/sys/extensions/device.lua b/sys/extensions/device.lua
index 0b1eee3..a67c0a8 100644
--- a/sys/extensions/device.lua
+++ b/sys/extensions/device.lua
@@ -1,13 +1,5 @@
-if _G.device then
-  return
-end
-
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Peripheral = require('peripheral')
 
-_G.device = { }
-
-for _,side in pairs(peripheral.getNames()) do
-  Peripheral.addDevice(device, side)
-end
+_G.device = Peripheral.getList()
diff --git a/sys/extensions/tgps.lua b/sys/extensions/tgps.lua
index 923e784..efb7288 100644
--- a/sys/extensions/tgps.lua
+++ b/sys/extensions/tgps.lua
@@ -1,8 +1,10 @@
+local turtle = _G.turtle
+
 if not turtle or turtle.enableGPS then
   return
 end
 
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local GPS    = require('gps')
 local Config = require('config')
diff --git a/sys/extensions/tl3.lua b/sys/extensions/tl3.lua
index ce8c73f..66fcdb6 100644
--- a/sys/extensions/tl3.lua
+++ b/sys/extensions/tl3.lua
@@ -1,8 +1,12 @@
+local os         = _G.os
+local peripheral = _G.peripheral
+local turtle     = _G.turtle
+
 if not turtle or turtle.getPoint then
   return
 end
 
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Point        = require('point')
 local synchronized = require('sync')
@@ -379,7 +383,7 @@ end
 -- combine with setHeading
 function turtle.setNamedHeading(headingName)
   local headingInfo = namedHeadings[headingName]
-  if headingInfo then 
+  if headingInfo then
     return turtle.setHeading(headingInfo.heading)
   end
   return false, 'Invalid heading'
@@ -482,11 +486,11 @@ function turtle.moveTowardsX(dx)
 
   local direction = dx - turtle.point.x
   local move
-  
+
   if direction == 0 then
     return true
   end
-  
+
   if direction > 0 and turtle.point.heading == 0 or
      direction < 0 and turtle.point.heading == 2 then
     move = turtle.forward
@@ -510,7 +514,7 @@ function turtle.moveTowardsZ(dz)
   if direction == 0 then
     return true
   end
-  
+
   if direction > 0 and turtle.point.heading == 1 or
      direction < 0 and turtle.point.heading == 3 then
     move = turtle.forward
@@ -591,13 +595,13 @@ local function gotoEx(dx, dz, dy)
 
   -- determine the heading to ensure the least amount of turns
   -- first check is 1 turn needed - remaining require 2 turns
-  if turtle.point.heading == 0 and turtle.point.x <= dx or 
-     turtle.point.heading == 2 and turtle.point.x >= dx or 
-     turtle.point.heading == 1 and turtle.point.z <= dz or 
-     turtle.point.heading == 3 and turtle.point.z >= dz then 
+  if turtle.point.heading == 0 and turtle.point.x <= dx or
+     turtle.point.heading == 2 and turtle.point.x >= dx or
+     turtle.point.heading == 1 and turtle.point.z <= dz or
+     turtle.point.heading == 3 and turtle.point.z >= dz then
     -- maintain current heading
     -- nop
-  elseif dz > turtle.point.z and turtle.point.heading == 0 or 
+  elseif dz > turtle.point.z and turtle.point.heading == 0 or
          dz < turtle.point.z and turtle.point.heading == 2 or
          dx < turtle.point.x and turtle.point.heading == 1 or
          dx > turtle.point.x and turtle.point.heading == 3 then
@@ -719,7 +723,7 @@ function turtle.gotoY(dy)
       return false
     end
   end
-  
+
   while turtle.point.y < dy do
     if not turtle.up() then
       return false
@@ -969,10 +973,10 @@ function turtle.faceAgainst(pt, options) -- 4 sided
   for i = 0, 3 do
     local hi = turtle.getHeadingInfo(i)
 
-    table.insert(options.dest, { 
-      x = pt.x + hi.xd, 
-      z = pt.z + hi.zd, 
-      y = pt.y + hi.yd, 
+    table.insert(options.dest, {
+      x = pt.x + hi.xd,
+      z = pt.z + hi.zd,
+      y = pt.y + hi.yd,
       heading = (hi.heading + 2) % 4,
     })
   end
@@ -998,8 +1002,8 @@ function turtle.moveAgainst(pt, options) -- 6 sided
     end
 
     table.insert(options.dest, {
-      x = pt.x + hi.xd, 
-      z = pt.z + hi.zd, 
+      x = pt.x + hi.xd,
+      z = pt.z + hi.zd,
       y = pt.y + hi.yd,
       direction = direction,
       heading = heading,
@@ -1058,25 +1062,25 @@ local actionsAt = {
 }
 
 local function _actionAt(action, pt, ...)
-  local pt = turtle.moveAgainst(pt)
+  pt = turtle.moveAgainst(pt)
   if pt then
     return action[pt.direction](...)
   end
 end
 
-function _actionDownAt(action, pt, ...)
+local function _actionDownAt(action, pt, ...)
   if turtle.pathfind(Point.above(pt)) then
     return action.down(...)
   end
 end
 
-function _actionForwardAt(action, pt, ...)
+local function _actionForwardAt(action, pt, ...)
   if turtle.faceAgainst(pt) then
     return action.forward(...)
   end
 end
 
-function _actionUpAt(action, pt, ...)
+local function _actionUpAt(action, pt, ...)
   if turtle.pathfind(Point.below(pt)) then
     return action.up(...)
   end
diff --git a/sys/extensions/vfs.lua b/sys/extensions/vfs.lua
index 186a928..0b88927 100644
--- a/sys/extensions/vfs.lua
+++ b/sys/extensions/vfs.lua
@@ -2,9 +2,11 @@ if fs.native then
   return
 end
 
-requireInjector(getfenv(1))
+_G.requireInjector()
 local Util = require('util')
 
+local fs = _G.fs
+
 fs.native = Util.shallowCopy(fs)
 
 local fstypes = { }
@@ -18,7 +20,7 @@ for k,fn in pairs(fs) do
   end
 end
 
-function nativefs.list(node, dir, full)
+function nativefs.list(node, dir)
 
   local files
   if fs.native.isDir(dir) then
diff --git a/sys/network/snmp.lua b/sys/network/snmp.lua
index bf38d8b..04538d0 100644
--- a/sys/network/snmp.lua
+++ b/sys/network/snmp.lua
@@ -111,7 +111,7 @@ device.wireless_modem.open(999)
 print('discovery: listening on port 999')
 
 Event.on('modem_message', function(e, s, sport, id, info, distance)
-
+debug(info)
   if sport == 999 and tonumber(id) and type(info) == 'table' then
     if not network[id] then
       network[id] = { }
@@ -151,6 +151,7 @@ end
 
 -- every 10 seconds, send out this computer's info
 Event.onInterval(10, function()
+debug('timer')
   sendInfo()
   for _,c in pairs(_G.network) do
     local elapsed = os.clock()-c.timestamp
diff --git a/sys/services/device.lua b/sys/services/device.lua
index 3c2c2c1..5ea8941 100644
--- a/sys/services/device.lua
+++ b/sys/services/device.lua
@@ -1,9 +1,15 @@
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Event      = require('event')
 local Peripheral = require('peripheral')
 local Util       = require('util')
 
+local colors     = _G.colors
+local device     = _G.device
+local multishell = _ENV.multishell
+local os         = _G.os
+local term       = _G.term
+
 multishell.setTitle(multishell.getCurrent(), 'Devices')
 
 local attachColor = colors.green
@@ -14,7 +20,7 @@ if not term.isColor() then
   detachColor = colors.lightGray
 end
 
-Event.on('peripheral', function(event, side)
+Event.on('peripheral', function(_, side)
   if side then
     local dev = Peripheral.addDevice(device, side)
     if dev then
@@ -25,7 +31,7 @@ Event.on('peripheral', function(event, side)
   end
 end)
 
-Event.on('peripheral_detach', function(event, side)
+Event.on('peripheral_detach', function(_, side)
   if side then
     local dev = Util.find(device, 'side', side)
     if dev then
diff --git a/sys/services/gpshost.lua b/sys/services/gpshost.lua
index 119cbd4..c4380f9 100644
--- a/sys/services/gpshost.lua
+++ b/sys/services/gpshost.lua
@@ -1,6 +1,6 @@
 if device.wireless_modem then
 
-  requireInjector(getfenv(1))
+  _G.requireInjector()
   local Config = require('config')
 
   local config = { }
diff --git a/sys/services/log.lua b/sys/services/log.lua
index 1ccf3b8..7e957f8 100644
--- a/sys/services/log.lua
+++ b/sys/services/log.lua
@@ -1,14 +1,17 @@
-requireInjector(getfenv(1))
+_G.requireInjector()
 
 local Terminal = require('terminal')
 local Util     = require('util')
 
+local multishell = _ENV.multishell
+local os         = _G.os
+local term       = _G.term
+
 multishell.setTitle(multishell.getCurrent(), 'Debug')
 
 term.redirect(Terminal.scrollable(term.current(), 50))
 
 local tabId = multishell.getCurrent()
-local tab = multishell.getTab(tabId)
 local terminal = term.current()
 local previousId