diff --git a/sys/apps/shell.lua b/sys/apps/shell.lua
index 52dcc33..54eeb2c 100644
--- a/sys/apps/shell.lua
+++ b/sys/apps/shell.lua
@@ -52,8 +52,8 @@ local function run(...)
 		loadFn = loadfile
 	end
 
-	local bill, err = loadFn(path, env)
-	if not bill then
+	local funkshun, err = loadFn(path, env)
+	if not funkshun then
 		error(err, -1)
 	end
 
@@ -68,7 +68,7 @@ local function run(...)
 	}
 
 	env[ "arg" ] = { [0] = path, table.unpack(args) }
-	local r = { bill(table.unpack(args)) }
+	local r = { funkshun(table.unpack(args)) }
 
 	tProgramStack[#tProgramStack] = nil
 
@@ -659,7 +659,7 @@ local function shellRead(history)
 	return entry.value or ''
 end
 
-local history = History.load('usr/.shell_history', 25)
+local history = History.load('usr/.shell_history', 100)
 
 term.setBackgroundColor(_colors.backgroundColor)
 --term.clear()
diff --git a/sys/init/2.vfs.lua b/sys/init/2.vfs.lua
index b0e2ea7..e2406dc 100644
--- a/sys/init/2.vfs.lua
+++ b/sys/init/2.vfs.lua
@@ -100,26 +100,6 @@ end
 function nativefs.delete(node, dir)
 	if node.mountPoint == dir then
 		fs.unmount(dir)
-		-- hack here
-		-- if a file is mounted over an existing directory
-		-- ie. sys/apps/MOUNT.LUA
-		-- then sys and sys/apps are created as temp nodes
-		-- therefore, trying to delete sys was only
-		-- removing the node and not deleting the directory
-		-- Need a better way to backfill nodes in a way
-		-- that preserves the vfs functionality
-
-		-- perhaps a flag that denotes that this
-		-- file/directory is the actual mount
-
-		-- this hack will not fix
-		-- rm packages/common
-		-- where packages is linked from a drive
-		-- and urls are mounted under packages/common
-		-- (as the fstype will be linkfs)
-		if node.fstype == 'nativefs' then
-			fs.native.delete(dir)
-		end
 	else
 		fs.native.delete(dir)
 	end
@@ -316,11 +296,6 @@ function fs.mount(path, fstype, ...)
 			end
 			if not tp.nodes[d] then
 				tp.nodes[d] = Util.shallowCopy(tp)
-
-				if tp.nodes[d].source then
-					tp.nodes[d].source = fs.combine(tp.nodes[d].source, d)
-				end
-
 				tp.nodes[d].nodes = { }
 				tp.nodes[d].mountPoint = fs.combine(tp.mountPoint, d)
 			end
diff --git a/sys/init/3.sys.lua b/sys/init/3.sys.lua
index 7e18d18..ace7684 100644
--- a/sys/init/3.sys.lua
+++ b/sys/init/3.sys.lua
@@ -1,3 +1,42 @@
-local fs = _G.fs
+local fs     = _G.fs
+local os     = _G.os
 
 fs.loadTab('sys/etc/fstab')
+
+-- add some Lua compatibility functions
+function os.remove(a)
+	if fs.exists(a) then
+        local s = pcall(fs.delete, a)
+        return s and true or nil, a .. ': Unable to remove file'
+	end
+	return nil, a .. ': No such file or directory'
+end
+
+os.execute = function(cmd)
+    if not cmd then
+        return 1
+    end
+
+    local env = _G.getfenv(2)
+    local s, m = env.shell.run('sys/apps/shell.lua ' .. cmd)
+
+    if not s then
+        return 1, m
+    end
+
+    return 0
+end
+
+os.tmpname = function()
+    local fname
+    repeat
+        fname = 'tmp/a' .. math.random(1, 32768)
+    until not fs.exists(fname)
+
+    return fname
+end
+
+-- non-standard - will raise error instead
+os.exit = function(code)
+    error('Terminated with ' .. code)
+end
diff --git a/sys/init/7.multishell.lua b/sys/init/7.multishell.lua
index 3930eae..e7bb1e2 100644
--- a/sys/init/7.multishell.lua
+++ b/sys/init/7.multishell.lua
@@ -144,6 +144,9 @@ function multishell.openTab(env, tab)
 				end
 			end
 		end
+		if tab.chainExit then
+			tab.chainExit(self, result, err, stack)
+		end
 	end
 
 	local routine, message = kernel.run(env, tab)
diff --git a/sys/modules/opus/fs/linkfs.lua b/sys/modules/opus/fs/linkfs.lua
index 8ffdb4c..813ce5f 100644
--- a/sys/modules/opus/fs/linkfs.lua
+++ b/sys/modules/opus/fs/linkfs.lua
@@ -5,7 +5,7 @@ local linkfs = { }
 -- TODO: implement broken links
 
 local methods = { 'exists', 'getFreeSpace', 'getSize', 'attributes',
-	'isDir', 'isReadOnly', 'list', 'listEx', 'makeDir', 'open', 'getDrive' }
+	'isDir', 'isReadOnly', 'list', 'makeDir', 'open', 'getDrive' }
 
 for _,m in pairs(methods) do
 	linkfs[m] = function(node, dir, ...)
@@ -18,7 +18,7 @@ function linkfs.resolve(node, dir)
 	return dir:gsub(node.mountPoint, node.source, 1)
 end
 
-function linkfs.mount(_, source)
+function linkfs.mount(path, source)
 	if not source then
 		error('Source is required')
 	end
@@ -26,6 +26,9 @@ function linkfs.mount(_, source)
 	if not fs.exists(source) then
 		error('Source is missing')
 	end
+	if path == source then
+		return
+	end
 	if fs.isDir(source) then
 		return {
 			source = source,
diff --git a/sys/modules/opus/fs/urlfs.lua b/sys/modules/opus/fs/urlfs.lua
index 96b7854..b2c47ca 100644
--- a/sys/modules/opus/fs/urlfs.lua
+++ b/sys/modules/opus/fs/urlfs.lua
@@ -5,15 +5,19 @@ local fs = _G.fs
 
 local urlfs = { }
 
-function urlfs.mount(_, url)
+function urlfs.mount(path, url, force)
 	if not url then
 		error('URL is required')
 	end
-	return {
-		url = url,
-		created = os.epoch('utc'),
-		modification = os.epoch('utc'),
-	}
+
+	-- only mount if the file does not exist already
+	if not fs.exists(path) or force then
+		return {
+			url = url,
+			created = os.epoch('utc'),
+			modification = os.epoch('utc'),
+		}
+	end
 end
 
 function urlfs.attributes(node)
@@ -38,7 +42,7 @@ function urlfs.getSize(node)
 end
 
 function urlfs.isReadOnly()
-	return true
+	return false
 end
 
 function urlfs.isDir()
diff --git a/sys/modules/opus/injector.lua b/sys/modules/opus/injector.lua
index aea109a..17a17f1 100644
--- a/sys/modules/opus/injector.lua
+++ b/sys/modules/opus/injector.lua
@@ -89,6 +89,7 @@ return function(env)
 			os     = os,
 			string = string,
 			table  = table,
+			debug  = debug,
 		},
 		loaders = {
 			preloadSearcher,