diff --git a/commands/update.lua b/commands/update.lua
index 90a126a..3a6944f 100644
--- a/commands/update.lua
+++ b/commands/update.lua
@@ -1,3 +1,4 @@
+
 return function ()
   local log = require('log').log
   local core = require('core')()
@@ -20,6 +21,13 @@ return function ()
     return body
   end
 
+  local isWindows
+  if _G.jit then
+    isWindows = _G.jit.os == "Windows"
+  else
+    isWindows = not not package.path:match("\\")
+  end
+
   -- Returns current version, latest version and latest compat version.
   local function checkUpdate()
     -- Read the current lit version
@@ -63,7 +71,7 @@ return function ()
       local stdout = exec(target, "-v")
       if not stdout:match("^lit version:") then
         target = pathJoin(target, "..", "lit")
-        if jit.os == "Windows" then
+        if isWindows then
           target = target .. ".exe"
         end
       end
@@ -107,7 +115,7 @@ return function ()
 
   do
     local luvitPath = pathJoin(uv.exepath(), "..", "luvit")
-    if jit.os == "Windows" then
+    if isWindows then
       luvitPath = luvitPath .. ".exe"
     end
     if uv.fs_stat(luvitPath) then
@@ -123,14 +131,14 @@ return function ()
 
   do
     local target = pathJoin(uv.exepath(), "..", "luvi")
-    if jit.os == "Windows" then
+    if isWindows then
       target = target .. ".exe"
     end
     local new, old
     local toupdate = require('luvi').version
     if uv.fs_stat(target) then
       local stdout = exec(target, "-v")
-      if jit.os == "Windows" then
+      if isWindows then
         stdout = stdout:gsub("luvi.exe ","luvi ")
       end
       local version = stdout:match("luvi (v[^ \r\n]+)")
diff --git a/deps/coro-channel.lua b/deps/coro-channel.lua
index 647b539..13efa2d 100644
--- a/deps/coro-channel.lua
+++ b/deps/coro-channel.lua
@@ -1,6 +1,6 @@
 --[[lit-meta
   name = "luvit/coro-channel"
-  version = "3.0.4"
+  version = "3.0.5"
   homepage = "https://github.com/luvit/lit/blob/master/deps/coro-channel.lua"
   description = "An adapter for wrapping uv streams as coro-streams."
   tags = {"coro", "adapter"}
@@ -8,7 +8,7 @@
   author = { name = "Tim Caswell" }
 ]]
 
--- local p = require('pretty-print').prettyPrint
+local unpack = unpack or table.unpack
 
 local function assertResume(thread, ...)
   local success, err = coroutine.resume(thread, ...)
diff --git a/deps/coro-http.lua b/deps/coro-http.lua
index 454dda0..b4cd785 100644
--- a/deps/coro-http.lua
+++ b/deps/coro-http.lua
@@ -1,6 +1,6 @@
 --[[lit-meta
   name = "luvit/coro-http"
-  version = "3.2.3"
+  version = "3.2.4"
   dependencies = {
     "luvit/coro-net@3.3.0",
     "luvit/http-codec@3.0.0"
@@ -14,6 +14,7 @@
 
 local httpCodec = require('http-codec')
 local net = require('coro-net')
+local unpack = unpack or table.unpack
 
 local function createServer(host, port, onConnect)
   return net.createServer({
diff --git a/deps/coro-split.lua b/deps/coro-split.lua
index 0c6058c..61c69b4 100644
--- a/deps/coro-split.lua
+++ b/deps/coro-split.lua
@@ -1,6 +1,6 @@
 --[[lit-meta
   name = "luvit/coro-split"
-  version = "2.0.2"
+  version = "2.0.3"
   homepage = "https://github.com/luvit/lit/blob/master/deps/coro-split.lua"
   description = "An coro style helper for running tasks concurrently."
   tags = {"coro", "split"}
@@ -11,6 +11,7 @@
 -- Split takes several functions as input and runs them in concurrent coroutines.
 -- The split function will itself block and wait for all three to finish.
 -- The results of the functions will be returned from split.
+local unpack = unpack or table.unpack
 
 local function assertResume(thread, ...)
   local success, err = coroutine.resume(thread, ...)
diff --git a/deps/http-codec.lua b/deps/http-codec.lua
index cb3a181..a1bb061 100644
--- a/deps/http-codec.lua
+++ b/deps/http-codec.lua
@@ -18,7 +18,7 @@ limitations under the License.
 
 --[[lit-meta
   name = "luvit/http-codec"
-  version = "3.0.7"
+  version = "3.0.8"
   homepage = "https://github.com/luvit/luvit/blob/master/deps/http-codec.lua"
   description = "A simple pair of functions for converting between hex and raw strings."
   tags = {"codec", "http"}
@@ -33,6 +33,7 @@ local find = string.find
 local format = string.format
 local concat = table.concat
 local match = string.match
+local unpack = unpack or table.unpack
 
 local STATUS_CODES = {
   [100] = 'Continue',
diff --git a/deps/readline.lua b/deps/readline.lua
index 3061fe9..b11c64c 100644
--- a/deps/readline.lua
+++ b/deps/readline.lua
@@ -17,7 +17,7 @@ limitations under the License.
 --]]
 --[[lit-meta
   name = "luvit/readline"
-  version = "2.2.0"
+  version = "2.2.1"
   dependencies = {
     "luvit/ustring@2.0.0",
   }
@@ -29,6 +29,7 @@ limitations under the License.
 ]]
 
 -- Heavily inspired by ljlinenoise : <http://fperrad.github.io/ljlinenoise/>
+local unpack = unpack or table.unpack
 
 local ustring = require "ustring"
 local emptyline = ustring.new()
diff --git a/deps/weblit-auto-headers.lua b/deps/weblit-auto-headers.lua
index d62899d..56030b7 100644
--- a/deps/weblit-auto-headers.lua
+++ b/deps/weblit-auto-headers.lua
@@ -28,6 +28,7 @@ Response automatic values:
 ]]
 
 local date = require('os').date
+local unpack = unpack or table.unpack
 
 local success, parent = pcall(require, '../package')
 local serverName = success and (parent.name .. " v" .. parent.version)
diff --git a/deps/weblit-server.lua b/deps/weblit-server.lua
index 6a07895..47d28eb 100644
--- a/deps/weblit-server.lua
+++ b/deps/weblit-server.lua
@@ -15,6 +15,7 @@
 local uv = require('uv')
 local createServer = require('coro-net').createServer
 local httpCodec = require('http-codec')
+local unpack = unpack or table.unpack
 
 -- Provide a nice case insensitive interface to headers.
 local headerMeta = {}
diff --git a/deps/websocket-codec.lua b/deps/websocket-codec.lua
index 6a2c492..6348f8c 100644
--- a/deps/websocket-codec.lua
+++ b/deps/websocket-codec.lua
@@ -1,7 +1,7 @@
 --[[lit-meta
   name = "luvit/websocket-codec"
   description = "A codec implementing websocket framing and helpers for handshakeing"
-  version = "3.0.2"
+  version = "3.0.3"
   dependencies = {
     "luvit/base64@2.0.0",
     "luvit/sha1@1.0.0",
@@ -30,6 +30,7 @@ local gsub = string.gsub
 local concat = table.concat
 local floor = math.floor
 local random = math.random
+local unpack = unpack or table.unpack
 
 local function rand4()
   -- Generate 32 bits of pseudo random data
diff --git a/libs/api.lua b/libs/api.lua
index 938ac11..03736e9 100644
--- a/libs/api.lua
+++ b/libs/api.lua
@@ -84,6 +84,7 @@ local ffi = require('ffi')
 local fs = require('coro-fs')
 local metrics = require('metrics')
 local uv = require('uv')
+local unpack = unpack or table.unpack
 
 local function hex_to_char(x)
   return string.char(tonumber(x, 16))
@@ -173,19 +174,15 @@ local function collectStats()
     return entries
   end
 
-  local howToDetermineFDs = {
-    Linux = function() return countFDs("/proc/self/fd") end,
-    OSX = function() return countFDs("/dev/fd") end,
-    Other = function() return -1 end
-  }
-
-  local os = ffi.os
-  if howToDetermineFDs[os] == nil then
-    os = "Other"
+  local numFDs = -1
+  if fs.exists("/proc/self/fd") then
+    numFDs = countFDs("/proc/self/fd")
+  elseif fs.exists("/dev/fd") then
+    numFDs = countFDs("/dev/fd")
   end
 
   metrics.set("lua.mem.used", memoryUsed)
-  metrics.set("lua.fds.used", howToDetermineFDs[os]())
+  metrics.set("lua.fds.used", numFDs)
   return metrics.all()
 end
 
diff --git a/libs/autoconfig.lua b/libs/autoconfig.lua
index e4be0db..69aad64 100644
--- a/libs/autoconfig.lua
+++ b/libs/autoconfig.lua
@@ -21,7 +21,7 @@ local fs = require('coro-fs')
 local env = require('env')
 
 local prefix
-if require('ffi').os == "Windows" then
+if package.config:sub(1,1) == '\\' and env.get('APPDATA') then
   prefix = env.get("APPDATA") .. "\\"
 else
   prefix = env.get("HOME") .. "/."
diff --git a/libs/core.lua b/libs/core.lua
index 7fecd12..73ccba1 100644
--- a/libs/core.lua
+++ b/libs/core.lua
@@ -54,6 +54,7 @@ local exportZip = require('export-zip')
 local digest = require('openssl').digest.digest
 local request = require('coro-http').request
 local makeAutoConfig = require('autoconfig')
+local unpack = unpack or table.unpack
 
 local quotepattern = '(['..("%^$().[]*+-?"):gsub("(.)", "%%%1")..'])'
 local function escape(str)
@@ -69,6 +70,13 @@ local function run(...)
   end
 end
 
+local isWindows
+if _G.jit then
+  isWindows = _G.jit.os == "Windows"
+else
+  isWindows = not not package.path:match("\\")
+end
+
 -- Takes a time struct with a date and time in UTC and converts it into
 -- seconds since Unix epoch (0:00 1 Jan 1970 UTC).
 -- Trickier than you'd think because os.time assumes the struct is in local time.
@@ -181,11 +189,16 @@ local function makeCore(config)
     local version = semver.normalize(meta and meta.version or luvi.version)
     local template = meta and meta.url or defaultTemplate
     local arch
-    if jit.os == "Windows" then
-      if jit.arch == "x64" then
+    if isWindows then
+      local info = uv.os_uname()
+      if info.machine == 'amd64' then
         arch = "Windows-amd64.exe"
       else
-        arch = "Windows-ia32.exe"
+        if semver.gte(version, '2.15.0') then
+          arch = "Windows-x86.exe" -- the new name scheme
+        else
+          arch = "Windows-ia32.exe"
+        end
       end
     else
       arch = run("uname", "-s") .. "_" .. run("uname", "-m")
@@ -202,7 +215,7 @@ local function makeCore(config)
     if template == defaultTemplate and flavor == "regular" and version == semver.normalize(luvi.version) then
       local exe = uv.exepath()
       local stdout = exec(exe, "-v")
-      if jit.os == "Windows" then
+      if isWindows then
         stdout = stdout:gsub('.exe','')
       end
       local iversion = stdout:match("luvi version: v(%d+%.%d+%.%d+)")
@@ -367,7 +380,7 @@ local function makeCore(config)
   end
 
   local function makeZip(rootHash, target, luvi_source)
-    if jit.os == "Windows" and (not target:match('%.exe$')) then
+    if isWindows and (not target:match('%.exe$')) then
       target = target..'.exe'
     end
 
@@ -401,7 +414,7 @@ local function makeCore(config)
 
   local function defaultTarget(meta)
     local target = meta.target or meta.name:match("[^/]+$")
-    if jit.os == "Windows" then
+    if isWindows then
       target = target .. ".exe"
     end
     return target
diff --git a/libs/db-fs.lua b/libs/db-fs.lua
index a7fd9cf..a3214be 100644
--- a/libs/db-fs.lua
+++ b/libs/db-fs.lua
@@ -20,6 +20,7 @@ local git = require('git')
 local listToMap = git.listToMap
 local modeToType = git.modes.toType
 local modes = git.modes
+local unpack = unpack or table.unpack
 
 return function (db, root)
   local cache = {}
diff --git a/libs/export-zip.lua b/libs/export-zip.lua
index 4ab20eb..a9cbb18 100644
--- a/libs/export-zip.lua
+++ b/libs/export-zip.lua
@@ -19,6 +19,7 @@ limitations under the License.
 local miniz = require('miniz')
 local modes = require('git').modes
 local log = require('log').log
+local loadstring = loadstring or load
 
 -- Create a zip from a hash optionally compiling lua files to bytecode.
 return function (db, rootHash, compileLua)
diff --git a/libs/handlers.lua b/libs/handlers.lua
index bae87a3..eaa7569 100644
--- a/libs/handlers.lua
+++ b/libs/handlers.lua
@@ -22,6 +22,7 @@ local digest = require('openssl').digest.digest
 local githubQuery = require('github-request')
 local jsonParse = require('json').parse
 local verifySignature = require('verify-signature')
+local unpack = unpack or table.unpack
 
 local function split(line)
   local args = {}
diff --git a/libs/import.lua b/libs/import.lua
index db61742..cb80101 100644
--- a/libs/import.lua
+++ b/libs/import.lua
@@ -20,6 +20,7 @@ local pathJoin = require('luvi').path.join
 local isAllowed = require('rules').isAllowed
 local compileFilter = require('rules').compileFilter
 local modes = require('git').modes
+local loadstring = loadstring or load
 
 -- Import a fs path into the database
 return function (db, fs, rootpath, rules, nativeOnly)
diff --git a/libs/pkg.lua b/libs/pkg.lua
index 8081bfe..894586c 100644
--- a/libs/pkg.lua
+++ b/libs/pkg.lua
@@ -32,6 +32,15 @@ local semver = require('semver')
 local pathJoin = require('luvi').path.join
 local listToMap = require('git').listToMap
 local jsonParse = require('json').parse
+local load = load
+if not load then
+  function load(code, name, mode, env)
+    local fn, err = loadstring(code, name)
+    if not fn then return fn, err end
+    if env then setfenv(fn, env) end
+    return fn
+  end
+end
 
 local function evalModule(data, name)
   -- Match multiline lua comments that start with `lit-meta`
@@ -40,21 +49,19 @@ local function evalModule(data, name)
     local term = "]" .. data:sub(a + 3, b - 9) .."]"
     local c = data:find(term, b + 1, true)
     if c then
-      local fn, err = loadstring(data:sub(b + 1, c - 1), name)
-      assert(not err, err)
       local env = {}
-      setfenv(fn, env)
+      local fn, err = load(data:sub(b + 1, c - 1), name, "t", env)
+      assert(not err, err)
       assert(pcall(fn))
       return env
     end
   end
-  local fn, err = loadstring(data, name)
-  if not fn then return nil, err end
   local exports = {}
   local module = { exports = exports }
-  setfenv(fn, {
+  local fn, err = load(data, name, 't', {
     exports = exports,
   })
+  if not fn then return nil, err end
   local success, ret = pcall(fn)
 
   local meta = success and type(ret) == "table" and ret or module.exports
diff --git a/libs/rules.lua b/libs/rules.lua
index 92cebb5..f914157 100644
--- a/libs/rules.lua
+++ b/libs/rules.lua
@@ -16,21 +16,29 @@ limitations under the License.
 
 --]]
 
-local ffi = require('ffi')
 local log = require('log').log
 local pathJoin = require('luvi').path.join
 local modes = require('git').modes
 local colorize = require('pretty-print').colorize
+local unpack = unpack or table.unpack
+local loadstring = loadstring or load
 
 local quotepattern = '['..("%^$().[]*+-?"):gsub("(.)", "%%%1")..']'
 
+local native_os, native_arch
+do
+  local info = require('luv').os_uname()
+  native_os = info.sysname
+  native_arch = info.machine
+end
+
 -- When importing into the db to publish, we want to include binaries for all
 -- platforms, but when installing to disk or zip app bundle, we want native only.
 local patterns = {
   -- Rough translation of (Linux|Windows|OSX|BSD) and (x86|x64|arm)
   -- This is more liberal than it needs to be, but works mostly in practice.
   all = {"[LWOB][iS][nXD][uxdows]*", "[xa][86r][64m]"},
-  native = {ffi.os, ffi.arch},
+  native = {native_os, native_arch},
 }
 
 local function compileFilter(rootPath, rules, nativeOnly)
diff --git a/libs/stats.lua b/libs/stats.lua
index 2deb540..1934533 100644
--- a/libs/stats.lua
+++ b/libs/stats.lua
@@ -1,7 +1,7 @@
 local jsonStringify = require('json').stringify
 local uv = require('uv')
 local scandir = require('coro-fs').scandir
-local ffi = require('ffi')
+local exists = require('coro-fs').exists
 
 return function (_, res)
   local handles = {}
@@ -22,10 +22,10 @@ return function (_, res)
   local memoryUsed = 1024 * collectgarbage("count")
 
   -- Count file descriptors
-  local path = ({
-    Linux = "/proc/self/fd",
-    OSX = "/dev/fd"
-  })[ffi.os]
+  local path = "/proc/self/fd"
+  if not exists(path) then
+    path = "/dev/fd"
+  end
   local entries = 0
   local iter = scandir(path)
   for _ in iter do
diff --git a/luvit-loader.lua b/luvit-loader.lua
index c5a9d6b..10b820b 100644
--- a/luvit-loader.lua
+++ b/luvit-loader.lua
@@ -27,6 +27,7 @@ else
 end
 
 local getenv = require('os').getenv
+local loadstring = loadstring or load
 
 local isWindows
 if _G.jit then
@@ -139,10 +140,51 @@ local function pathJoin(...)
   return path
 end
 
-local function loader(dir, path, bundleOnly)
+local function loader(path, fullPath)
+  local useBundle = fullPath:sub(1, 7) == "bundle:"
+  if useBundle then
+    fullPath = fullPath:sub(8)
+  end
+  if useBundle then
+    local key = "bundle:" .. fullPath
+    if package.loaded[key] then
+      return package.loaded[key]
+    end
+    local code = bundle.readfile(fullPath)
+    local module = loadstring(code, key)(key)
+    package.loaded[key] = module
+    return module
+  end
+  fullPath = uv.fs_realpath(fullPath)
+  if package.loaded[fullPath] then
+    return package.loaded[fullPath]
+  end
+  local module = assert(loadfile(fullPath))(fullPath)
+  package.loaded[fullPath] = module
+  return module
+end
+
+local cwd = uv.cwd()
+local function searcher(path)
+  local level, caller = 3
+  -- Loop past any C functions to get to the real caller
+  -- This avoids pcall(require, "path") getting "=C" as the source
+  repeat
+    caller = debug.getinfo(level, "S").source
+    level = level + 1
+  until caller ~= "=[C]"
+
+  local dir
   local errors = {}
   local fullPath
-  local useBundle = bundleOnly
+  local useBundle = false
+  if string.sub(caller, 1, 1) == "@" then
+    dir = pathJoin(cwd, caller:sub(2), "..")
+  elseif string.sub(caller, 1, 7) == "bundle:" then
+    useBundle = true
+    dir = pathJoin(caller:sub(8), "..")
+  end
+
   local function try(tryPath)
     local prefix = useBundle and "bundle:" or ""
     local fileStat = useBundle and bundle.stat or uv.fs_stat
@@ -191,47 +233,26 @@ local function loader(dir, path, bundleOnly)
     -- Module require
   end
   if useBundle then
-    local key = "bundle:" .. fullPath
-    return function ()
-      if package.loaded[key] then
-        return package.loaded[key]
-      end
-      local code = bundle.readfile(fullPath)
-      local module = loadstring(code, key)(key)
-      package.loaded[key] = module
-      return module
-    end, key
-  end
-  fullPath = uv.fs_realpath(fullPath)
-  return function ()
-    if package.loaded[fullPath] then
-      return package.loaded[fullPath]
+    if bundle.stat(fullPath) then
+      return loader, 'bundle:' .. fullPath
+    end
+  else
+    if uv.fs_access(fullPath) then
+      return loader, fullPath
     end
-    local module = assert(loadfile(fullPath))(fullPath)
-    package.loaded[fullPath] = module
-    return module
   end
 end
 
 -- Register as a normal lua package loader.
-local cwd = uv.cwd()
-table.insert(package.loaders, 1, function (path)
-
-  -- Ignore built-in libraries with this loader.
-  if path:match("^[a-z]+$") and package.preload[path] then
-    return
-  end
+if package.loaders then
+  table.insert(package.loaders, 1, function (path)
+    local loader_fn, loader_data = searcher(path)
+    if not loader_fn then
+      return nil
+    end
 
-  local level, caller = 3
-  -- Loop past any C functions to get to the real caller
-  -- This avoids pcall(require, "path") getting "=C" as the source
-  repeat
-    caller = debug.getinfo(level, "S").source
-    level = level + 1
-  until caller ~= "=[C]"
-  if string.sub(caller, 1, 1) == "@" then
-    return loader(pathJoin(cwd, caller:sub(2), ".."), path)
-  elseif string.sub(caller, 1, 7) == "bundle:" then
-    return loader(pathJoin(caller:sub(8), ".."), path, true)
-  end
-end)
+    return loader(path, loader_data)
+  end)
+else
+  table.insert(package.searchers, 1, searcher)
+end
\ No newline at end of file
diff --git a/main.lua b/main.lua
index 2fb04b3..4abcaf2 100644
--- a/main.lua
+++ b/main.lua
@@ -16,6 +16,8 @@ limitations under the License.
 
 --]]
 
+local loadstring = loadstring or load
+
 local bundle = require("luvi").bundle
 loadstring(bundle.readfile("luvit-loader.lua"), "bundle:luvit-loader.lua")()
 
diff --git a/tests/main.lua b/tests/main.lua
index 6a2618e..e7aea9f 100644
--- a/tests/main.lua
+++ b/tests/main.lua
@@ -1,7 +1,10 @@
+local loadstring = loadstring or load
+
 local bundle = require('luvi').bundle
 loadstring(bundle.readfile("../luvit-loader.lua"), "bundle:luvit-loader.lua")()
 
 local uv = require('uv')
+local unpack = unpack or table.unpack
 
 coroutine.wrap(function ()
   local success, err = xpcall(function ()