diff --git a/.gitignore b/.gitignore
index ea0b1c5c6..77f5bd934 100644
--- a/.gitignore
+++ b/.gitignore
@@ -7,3 +7,4 @@ man7
 node_modules
 build
 .lock-wscript
+tags
diff --git a/CHANGELOG.md b/CHANGELOG.md
index db2889286..38b8c7a33 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,11 @@ zombie.js-changelog(7) -- Changelog
 
 ### Version 0.8.14  Pending
 
+New isolated contexts for executing JavaScript.
+
+    293 Tests
+    4.4 sec to complete
+
 
 ### Version 0.8.13  2011-02-11
 
diff --git a/Cakefile b/Cakefile
index bcc1a35b4..7df35e102 100644
--- a/Cakefile
+++ b/Cakefile
@@ -52,7 +52,9 @@ task "install", "Install Zombie in your local repository", ->
 build = (callback)->
   log "Compiling CoffeeScript to JavaScript ...", green
   exec "rm -rf lib && coffee -c -l -b -o lib src", (err, stdout)->
-    callback err
+    onerror err
+    log "Compiling native extension ...", green
+    exec "node-waf clean build", callback
 task "build", "Compile CoffeeScript to JavaScript", -> build onerror
 
 task "watch", "Continously compile CoffeeScript to JavaScript", ->
diff --git a/TODO.md b/TODO.md
index e584f0087..6f81b227a 100644
--- a/TODO.md
+++ b/TODO.md
@@ -9,13 +9,6 @@ zombie.js-todo(7) -- Wishlist
   * Make sure `DOMContentLoaded` event fires after all stylesheets
     are loaded
 
-* New script context
-  * The execution context for all scripts on the page is the `Window`
-    object itself
-  * Node's `runInContext` accepts a sandbox, then creates an actual V8
-    context by copying properties to/from, which breaks asynchronous
-    scripts (timer, XHR, etc) which run in the contex, not the sandbox
-
 * Navigation: Browser.open/close should work as a pair; look into supporting
   window.open; fire unload event when navigating away from page.
 
diff --git a/src/zombie/browser.coffee b/src/zombie/browser.coffee
index 44119fd54..a2b11d72d 100644
--- a/src/zombie/browser.coffee
+++ b/src/zombie/browser.coffee
@@ -5,7 +5,8 @@ require "./jsdom_patches"
 require "./forms"
 require "./xpath"
 History = require("./history").History
-
+require.paths.push "../../build/default"
+WindowContext = require("../../build/default/windowcontext").WindowContext
 
 
 # Use the browser to open up new windows and load documents.
@@ -78,10 +79,6 @@ class Browser extends require("events").EventEmitter
     # Windows
     # -------
 
-    require.paths.push "build/default"
-    WindowContext = require("windowcontext").WindowContext
-    
-
     window = null
     # ### browser.open() => Window
     #
@@ -94,36 +91,9 @@ class Browser extends require("events").EventEmitter
       history = features.history || new History
 
       newWindow = jsdom.createWindow(html)
+      # Add context for evaluating scripts.
       newWindow._evalContext = new WindowContext(newWindow)
-      global = newWindow._evalContext.global
-      global.decodeURI = decodeURI
-      global.decodeURIComponent = decodeURIComponent
-      global.encodeURI = encodeURI
-      global.encodeURIComponent = encodeURIComponent
-      global.escape = escape
-      global.eval = eval
-      global.isFinite = isFinite
-      global.isNaN = isNaN
-      global.parseFloat = parseFloat
-      global.parseInt = parseInt
-      global.unescape = unescape
-      global.Array = [].constructor
-      global.Boolean = Boolean
-      global.Date = Date
-      global.Error = Error
-      global.Function = Function
-      global.Math = Math
-      global.Number = Number
-      global.Object = {}.constructor
-      global.RegExp = //.constructor
-      global.String = newWindow._evalContext.evaluate("''.constructor")
-
-      newWindow._evaluate = (code, filename)->
-        try
-          newWindow._evalContext.evaluate(code, filename)
-        catch ex
-          console.log ex.message[0..500]
-          console.log ex.stack
+      newWindow._evaluate = (code, filename)-> newWindow._evalContext.evaluate(code, filename)
 
       # Switch to the newly created window if it's interactive.
       # Examples of non-interactive windows are frames.
diff --git a/src/zombie/windowcontext.cc b/src/zombie/windowcontext.cc
index 4273f6830..e9b2fdc86 100644
--- a/src/zombie/windowcontext.cc
+++ b/src/zombie/windowcontext.cc
@@ -4,6 +4,8 @@
 using namespace node;
 using namespace v8;
 
+// Isolated V8 Context/global scope for evaluating JavaScript, with access to
+// all window methods/properties.
 class WindowContext: ObjectWrap {
 private:
 
@@ -35,6 +37,27 @@ class WindowContext: ObjectWrap {
     this->global = Persistent<Object>::New(global);
     tmpl->SetNamedPropertyHandler(GetProperty, SetProperty, NULL, DeleteProperty, EnumerateProperties, this->global);
     context = Context::New(NULL, tmpl);
+
+    // Define constructor functions for primitives.  We need to do this within
+    // the context, so "foo".constructor == String
+    context->Enter();
+    global->Set(String::New("Array"), Script::New(String::New("[].constructor"))->Run());
+    global->Set(String::New("Boolean"), Script::New(String::New("true.constructor"))->Run());
+    global->Set(String::New("Function"), Script::New(String::New("(function() {}).constructor"))->Run());
+    global->Set(String::New("Number"), Script::New(String::New("(1).constructor"))->Run());
+    global->Set(String::New("Object"), Script::New(String::New("({}).constructor"))->Run());
+    global->Set(String::New("RegExp"), Script::New(String::New("/./.constructor"))->Run());
+    global->Set(String::New("String"), Script::New(String::New("''.constructor"))->Run());
+    context->Exit();
+    // FIX ME: Define constructors for non-primitive types.  We copy the
+    // constructor from Zombie's context, which is not a good thing.
+    const char* const list[] = { "Date", "Error", "Math", "decodeURI", "decodeURIComponent", "encodeURI", "encodeURIComponent",
+                                 "escape", "eval", "isFinite", "isNaN", "parseFloat", "parseInt", "unescape" };
+    const size_t len = sizeof(list) / sizeof(list[0]);
+    for (int i = len ; i-- >0 ; ) {
+      Handle<String> str = String::New(list[i]);
+      global->Set(str, Script::New(str)->Run());
+    }
   }
 
   ~WindowContext() {