diff --git a/documentation/css/docs.css b/documentation/css/docs.css
index b105dd83..9b455e45 100644
--- a/documentation/css/docs.css
+++ b/documentation/css/docs.css
@@ -43,7 +43,7 @@ table {
     td {
       padding: 9px 15px 9px 0;
     }
-code, pre, tt {
+code, pre, tt, textarea {
   font-family: Monaco, Consolas, "Lucida Console", monospace;
   font-size: 12px;
   line-height: 18px;
@@ -75,7 +75,7 @@ div.code {
     position: absolute;
     right: 8px; bottom: 8px;
   }
-  div.code pre {
+  div.code pre, div.code textarea {
     float: left;
     width: 450px;
     border-left: 1px dotted #559;
@@ -84,4 +84,15 @@ div.code {
   }
     div.code pre:first-child {
       border-left: 0;
-    }
\ No newline at end of file
+    }
+
+#repl_source {
+  border: 0;
+  padding: 5px 7px;
+  margin-left: 5px;
+  height: 250px;
+  resize: none;
+}
+#repl_results {
+  height: 260px;
+}
\ No newline at end of file
diff --git a/documentation/index.html.erb b/documentation/index.html.erb
index 1d339828..70bb5d37 100644
--- a/documentation/index.html.erb
+++ b/documentation/index.html.erb
@@ -59,6 +59,7 @@
     <p>
       <a href="#overview">Mini Overview</a><br />
       <a href="#installation">Installation and Usage</a><br />
+      <a href="#repl">Try CoffeeScript</a><br />
       <a href="#whitespace">Significant Whitespace</a><br />
       <a href="#functions">Functions and Invocation</a><br />
       <a href="#assignment">Assignment</a><br />
@@ -224,6 +225,25 @@ coffee --interactive
 coffee --watch --lint experimental.coffee
 coffee --print app/scripts/*.coffee > concatenation.js</pre>
 
+    <h2 id="repl">Try CoffeeScript</h2>
+
+    <p>
+      Here's a live version of the CoffeeScript compiler, running within
+      your browser.<br /> Hit the <b>compile</b> button to generate JavaScript 
+      on the right-hand side.
+      You can also paste in any of the examples from below.
+    </p>
+
+    <div class="code repl_wrapper">
+      <textarea id="repl_source">reverse: (string) -> 
+  string.split('').reverse()
+
+print reverse 'tpircseeffoc'</textarea>
+      <pre id="repl_results"></pre>
+      <button onclick="javascript: repl_compile();">compile</button>
+      <br class="clear" />
+    </div>
+
     <h2>Language Reference</h2>
 
     <p>
@@ -832,5 +852,18 @@ coffee --print app/scripts/*.coffee > concatenation.js</pre>
   <script type="text/javascript" src="lib/coffee_script/nodes.js"></script>
   <script type="text/javascript" src="lib/coffee_script/coffee-script.js"></script>
 
+  <script type="text/javascript">
+    window.repl_compile = function() {
+      var source = document.getElementById('repl_source').value;
+      var js = '';
+      try {
+        js = compile(source, {no_wrap: true});
+      } catch(error) {
+        alert(error);
+      }
+      document.getElementById('repl_results').innerHTML = js;
+    }
+  </script>
+
 </body>
 </html>
diff --git a/index.html b/index.html
index 12a24f77..4919d90a 100644
--- a/index.html
+++ b/index.html
@@ -45,6 +45,7 @@
     <p>
       <a href="#overview">Mini Overview</a><br />
       <a href="#installation">Installation and Usage</a><br />
+      <a href="#repl">Try CoffeeScript</a><br />
       <a href="#whitespace">Significant Whitespace</a><br />
       <a href="#functions">Functions and Invocation</a><br />
       <a href="#assignment">Assignment</a><br />
@@ -321,6 +322,25 @@ coffee --interactive
 coffee --watch --lint experimental.coffee
 coffee --print app/scripts/*.coffee > concatenation.js</pre>
 
+    <h2 id="repl">Try CoffeeScript</h2>
+
+    <p>
+      Here's a live version of the CoffeeScript compiler, running within
+      your browser.<br /> Hit the <b>compile</b> button to generate JavaScript 
+      on the right-hand side.
+      You can also paste in any of the examples from below.
+    </p>
+
+    <div class="code repl_wrapper">
+      <textarea id="repl_source">reverse: (string) -> 
+  string.split('').reverse()
+
+print reverse 'tpircseeffoc'</textarea>
+      <pre id="repl_results"></pre>
+      <button onclick="javascript: repl_compile();">compile</button>
+      <br class="clear" />
+    </div>
+
     <h2>Language Reference</h2>
 
     <p>
@@ -1703,5 +1723,18 @@ html <span class="Keyword">=</span> <span class="String"><span class="String">&q
   <script type="text/javascript" src="lib/coffee_script/nodes.js"></script>
   <script type="text/javascript" src="lib/coffee_script/coffee-script.js"></script>
 
+  <script type="text/javascript">
+    window.repl_compile = function() {
+      var source = document.getElementById('repl_source').value;
+      var js = '';
+      try {
+        js = compile(source, {no_wrap: true});
+      } catch(error) {
+        alert(error);
+      }
+      document.getElementById('repl_results').innerHTML = js;
+    }
+  </script>
+
 </body>
 </html>
diff --git a/lib/coffee_script/coffee-script.js b/lib/coffee_script/coffee-script.js
index 35846069..4df4dcaf 100644
--- a/lib/coffee_script/coffee-script.js
+++ b/lib/coffee_script/coffee-script.js
@@ -1,5 +1,6 @@
 (function(){
   var compiler, lexer, parser, path;
+  // Set up for both the browser and the server.
   if ((typeof process !== "undefined" && process !== null)) {
     process.mixin(require('./nodes'));
     path = require('path');
@@ -31,6 +32,10 @@
       return this.pos;
     }
   };
+  // Improved error messages.
+  parser.parseError = function parseError(message, hash) {
+    throw new Error('Unexpected ' + hash.token + ' on line ' + hash.line);
+  };
   exports.VERSION = '0.5.0';
   // Compile CoffeeScript to JavaScript, using the Coffee/Jison compiler.
   exports.compile = function compile(code, options) {
diff --git a/src/coffee-script.coffee b/src/coffee-script.coffee
index 4a03d1a7..ac8cfbc8 100644
--- a/src/coffee-script.coffee
+++ b/src/coffee-script.coffee
@@ -1,3 +1,4 @@
+# Set up for both the browser and the server.
 if process?
   process.mixin require './nodes'
   path:         require('path')
@@ -23,6 +24,10 @@ parser.lexer: {
   showPosition: -> @pos
 }
 
+# Improved error messages.
+parser.parseError: (message, hash) ->
+  throw new Error 'Unexpected ' + hash.token + ' on line ' + hash.line
+
 exports.VERSION: '0.5.0'
 
 # Compile CoffeeScript to JavaScript, using the Coffee/Jison compiler.
@@ -78,7 +83,3 @@ exports.ruby_compile_files: (paths, callback) ->
     return unless message
     puts message
     throw new Error "CoffeeScript compile error"
-
-
-
-