diff --git a/assets/scripts/vendor/handlebars.js b/assets/scripts/vendor/handlebars.js
index 247a3fdf..9c653ee7 100644
--- a/assets/scripts/vendor/handlebars.js
+++ b/assets/scripts/vendor/handlebars.js
@@ -1,3 +1,27 @@
+/*
+
+Copyright (C) 2011 by Yehuda Katz
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+
+*/
+
 // lib/handlebars/base.js
 
 /*jshint eqnull:true*/
@@ -5,7 +29,13 @@ this.Handlebars = {};
 
 (function(Handlebars) {
 
-Handlebars.VERSION = "1.0.rc.2";
+Handlebars.VERSION = "1.0.0-rc.3";
+Handlebars.COMPILER_REVISION = 2;
+
+Handlebars.REVISION_CHANGES = {
+  1: '<= 1.0.rc.2', // 1.0.rc.2 is actually rev2 but doesn't report it
+  2: '>= 1.0.0-rc.3'
+};
 
 Handlebars.helpers  = {};
 Handlebars.partials = {};
@@ -618,9 +648,13 @@ return new Parser;
 // lib/handlebars/compiler/base.js
 Handlebars.Parser = handlebars;
 
-Handlebars.parse = function(string) {
+Handlebars.parse = function(input) {
+
+  // Just return if an already-compile AST was passed in.
+  if(input.constructor === Handlebars.AST.ProgramNode) { return input; }
+
   Handlebars.Parser.yy = Handlebars.AST;
-  return Handlebars.Parser.parse(string);
+  return Handlebars.Parser.parse(input);
 };
 
 Handlebars.print = function(ast) {
@@ -702,8 +736,11 @@ Handlebars.print = function(ast) {
     for(var i=0,l=parts.length; i<l; i++) {
       var part = parts[i];
 
-      if(part === "..") { depth++; }
-      else if(part === "." || part === "this") { this.isScoped = true; }
+      if (part === ".." || part === "." || part === "this") {
+        if (dig.length > 0) { throw new Handlebars.Exception("Invalid path: " + this.original); }
+        else if (part === "..") { depth++; }
+        else { this.isScoped = true; }
+      }
       else { dig.push(part); }
     }
 
@@ -853,6 +890,26 @@ Handlebars.JavaScriptCompiler = function() {};
 
       return out.join("\n");
     },
+    equals: function(other) {
+      var len = this.opcodes.length;
+      if (other.opcodes.length !== len) {
+        return false;
+      }
+
+      for (var i = 0; i < len; i++) {
+        var opcode = this.opcodes[i],
+            otherOpcode = other.opcodes[i];
+        if (opcode.opcode !== otherOpcode.opcode || opcode.args.length !== otherOpcode.args.length) {
+          return false;
+        }
+        for (var j = 0; j < opcode.args.length; j++) {
+          if (opcode.args[j] !== otherOpcode.args[j]) {
+            return false;
+          }
+        }
+      }
+      return true;
+    },
 
     guid: 0,
 
@@ -944,7 +1001,7 @@ Handlebars.JavaScriptCompiler = function() {};
         // evaluate it by executing `blockHelperMissing`
         this.opcode('pushProgram', program);
         this.opcode('pushProgram', inverse);
-        this.opcode('pushHash');
+        this.opcode('emptyHash');
         this.opcode('blockValue');
       } else {
         this.ambiguousMustache(mustache, program, inverse);
@@ -953,7 +1010,7 @@ Handlebars.JavaScriptCompiler = function() {};
         // evaluate it by executing `blockHelperMissing`
         this.opcode('pushProgram', program);
         this.opcode('pushProgram', inverse);
-        this.opcode('pushHash');
+        this.opcode('emptyHash');
         this.opcode('ambiguousBlockValue');
       }
 
@@ -977,6 +1034,7 @@ Handlebars.JavaScriptCompiler = function() {};
 
         this.opcode('assignToHash', pair[0]);
       }
+      this.opcode('popHash');
     },
 
     partial: function(partial) {
@@ -1017,17 +1075,19 @@ Handlebars.JavaScriptCompiler = function() {};
     },
 
     ambiguousMustache: function(mustache, program, inverse) {
-      var id = mustache.id, name = id.parts[0];
+      var id = mustache.id,
+          name = id.parts[0],
+          isBlock = program != null || inverse != null;
 
       this.opcode('getContext', id.depth);
 
       this.opcode('pushProgram', program);
       this.opcode('pushProgram', inverse);
 
-      this.opcode('invokeAmbiguous', name);
+      this.opcode('invokeAmbiguous', name, isBlock);
     },
 
-    simpleMustache: function(mustache, program, inverse) {
+    simpleMustache: function(mustache) {
       var id = mustache.id;
 
       if (id.type === 'DATA') {
@@ -1158,7 +1218,7 @@ Handlebars.JavaScriptCompiler = function() {};
       if(mustache.hash) {
         this.hash(mustache.hash);
       } else {
-        this.opcode('pushHash');
+        this.opcode('emptyHash');
       }
 
       return params;
@@ -1175,7 +1235,7 @@ Handlebars.JavaScriptCompiler = function() {};
       if(mustache.hash) {
         this.hash(mustache.hash);
       } else {
-        this.opcode('pushHash');
+        this.opcode('emptyHash');
       }
 
       return params;
@@ -1189,7 +1249,7 @@ Handlebars.JavaScriptCompiler = function() {};
   JavaScriptCompiler.prototype = {
     // PUBLIC API: You can override these methods in a subclass to provide
     // alternative compiled forms for name lookup and buffering semantics
-    nameLookup: function(parent, name, type) {
+    nameLookup: function(parent, name /* , type*/) {
       if (/^[0-9]+$/.test(name)) {
         return parent + "[" + name + "]";
       } else if (JavaScriptCompiler.isValidJavaScriptVariableName(name)) {
@@ -1204,7 +1264,11 @@ Handlebars.JavaScriptCompiler = function() {};
       if (this.environment.isSimple) {
         return "return " + string + ";";
       } else {
-        return "buffer += " + string + ";";
+        return {
+          appendToBuffer: true,
+          content: string,
+          toString: function() { return "buffer += " + string + ";"; }
+        };
       }
     },
 
@@ -1225,6 +1289,7 @@ Handlebars.JavaScriptCompiler = function() {};
       this.isChild = !!context;
       this.context = context || {
         programs: [],
+        environments: [],
         aliases: { }
       };
 
@@ -1234,6 +1299,7 @@ Handlebars.JavaScriptCompiler = function() {};
       this.stackVars = [];
       this.registers = { list: [] };
       this.compileStack = [];
+      this.inlineStack = [];
 
       this.compileChildren(environment, options);
 
@@ -1255,11 +1321,11 @@ Handlebars.JavaScriptCompiler = function() {};
     },
 
     nextOpcode: function() {
-      var opcodes = this.environment.opcodes, opcode = opcodes[this.i + 1];
+      var opcodes = this.environment.opcodes;
       return opcodes[this.i + 1];
     },
 
-    eat: function(opcode) {
+    eat: function() {
       this.i = this.i + 1;
     },
 
@@ -1297,7 +1363,6 @@ Handlebars.JavaScriptCompiler = function() {};
 
       // Generate minimizer alias mappings
       if (!this.isChild) {
-        var aliases = [];
         for (var alias in this.context.aliases) {
           this.source[1] = this.source[1] + ', ' + alias + '=' + this.context.aliases[alias];
         }
@@ -1322,16 +1387,48 @@ Handlebars.JavaScriptCompiler = function() {};
         params.push("depth" + this.environment.depths.list[i]);
       }
 
+      // Perform a second pass over the output to merge content when possible
+      var source = this.mergeSource();
+
+      if (!this.isChild) {
+        var revision = Handlebars.COMPILER_REVISION,
+            versions = Handlebars.REVISION_CHANGES[revision];
+        source = "this.compilerInfo = ["+revision+",'"+versions+"'];\n"+source;
+      }
+
       if (asObject) {
-        params.push(this.source.join("\n  "));
+        params.push(source);
 
         return Function.apply(this, params);
       } else {
-        var functionSource = 'function ' + (this.name || '') + '(' + params.join(',') + ') {\n  ' + this.source.join("\n  ") + '}';
+        var functionSource = 'function ' + (this.name || '') + '(' + params.join(',') + ') {\n  ' + source + '}';
         Handlebars.log(Handlebars.logger.DEBUG, functionSource + "\n\n");
         return functionSource;
       }
     },
+    mergeSource: function() {
+      // WARN: We are not handling the case where buffer is still populated as the source should
+      // not have buffer append operations as their final action.
+      var source = '',
+          buffer;
+      for (var i = 0, len = this.source.length; i < len; i++) {
+        var line = this.source[i];
+        if (line.appendToBuffer) {
+          if (buffer) {
+            buffer = buffer + '\n    + ' + line.content;
+          } else {
+            buffer = line.content;
+          }
+        } else {
+          if (buffer) {
+            source += 'buffer += ' + buffer + ';\n  ';
+            buffer = undefined;
+          }
+          source += line + '\n  ';
+        }
+      }
+      return source;
+    },
 
     // [blockValue]
     //
@@ -1369,6 +1466,9 @@ Handlebars.JavaScriptCompiler = function() {};
       var current = this.topStack();
       params.splice(1, 0, current);
 
+      // Use the options value generated from the invocation
+      params[params.length-1] = 'options';
+
       this.source.push("if (!" + this.lastHelper + ") { " + current + " = blockHelperMissing.call(" + params.join(", ") + "); }");
     },
 
@@ -1392,6 +1492,9 @@ Handlebars.JavaScriptCompiler = function() {};
     // If `value` is truthy, or 0, it is coerced into a string and appended
     // Otherwise, the empty string is appended
     append: function() {
+      // Force anything that is inlined onto the stack so we don't have duplication
+      // when we examine local
+      this.flushInline();
       var local = this.popStack();
       this.source.push("if(" + local + " || " + local + " === 0) { " + this.appendToBuffer(local) + " }");
       if (this.environment.isSimple) {
@@ -1406,15 +1509,9 @@ Handlebars.JavaScriptCompiler = function() {};
     //
     // Escape `value` and append it to the buffer
     appendEscaped: function() {
-      var opcode = this.nextOpcode(), extra = "";
       this.context.aliases.escapeExpression = 'this.escapeExpression';
 
-      if(opcode && opcode.opcode === 'appendContent') {
-        extra = " + " + this.quotedString(opcode.args[0]);
-        this.eat(opcode);
-      }
-
-      this.source.push(this.appendToBuffer("escapeExpression(" + this.popStack() + ")" + extra));
+      this.source.push(this.appendToBuffer("escapeExpression(" + this.popStack() + ")"));
     },
 
     // [getContext]
@@ -1438,7 +1535,7 @@ Handlebars.JavaScriptCompiler = function() {};
     // Looks up the value of `name` on the current context and pushes
     // it onto the stack.
     lookupOnContext: function(name) {
-      this.pushStack(this.nameLookup('depth' + this.lastContext, name, 'context'));
+      this.push(this.nameLookup('depth' + this.lastContext, name, 'context'));
     },
 
     // [pushContext]
@@ -1486,7 +1583,7 @@ Handlebars.JavaScriptCompiler = function() {};
     //
     // Push the result of looking up `id` on the current data
     lookupData: function(id) {
-      this.pushStack(this.nameLookup('data', id, 'data'));
+      this.push(this.nameLookup('data', id, 'data'));
     },
 
     // [pushStringParam]
@@ -1509,13 +1606,25 @@ Handlebars.JavaScriptCompiler = function() {};
       }
     },
 
-    pushHash: function() {
-      this.push('{}');
+    emptyHash: function() {
+      this.pushStackLiteral('{}');
 
       if (this.options.stringParams) {
         this.register('hashTypes', '{}');
       }
     },
+    pushHash: function() {
+      this.hash = {values: [], types: []};
+    },
+    popHash: function() {
+      var hash = this.hash;
+      this.hash = undefined;
+
+      if (this.options.stringParams) {
+        this.register('hashTypes', '{' + hash.types.join(',') + '}');
+      }
+      this.push('{\n    ' + hash.values.join(',\n    ') + '\n  }');
+    },
 
     // [pushString]
     //
@@ -1534,7 +1643,8 @@ Handlebars.JavaScriptCompiler = function() {};
     //
     // Push an expression onto the stack
     push: function(expr) {
-      this.pushStack(expr);
+      this.inlineStack.push(expr);
+      return expr;
     },
 
     // [pushLiteral]
@@ -1577,12 +1687,14 @@ Handlebars.JavaScriptCompiler = function() {};
     invokeHelper: function(paramSize, name) {
       this.context.aliases.helperMissing = 'helpers.helperMissing';
 
-      var helper = this.lastHelper = this.setupHelper(paramSize, name);
-      this.register('foundHelper', helper.name);
+      var helper = this.lastHelper = this.setupHelper(paramSize, name, true);
 
-      this.pushStack("foundHelper ? foundHelper.call(" +
-        helper.callParams + ") " + ": helperMissing.call(" +
-        helper.helperMissingParams + ")");
+      this.push(helper.name);
+      this.replaceStack(function(name) {
+        return name + ' ? ' + name + '.call(' +
+            helper.callParams + ") " + ": helperMissing.call(" +
+            helper.helperMissingParams + ")";
+      });
     },
 
     // [invokeKnownHelper]
@@ -1594,7 +1706,7 @@ Handlebars.JavaScriptCompiler = function() {};
     // so a `helperMissing` fallback is not required.
     invokeKnownHelper: function(paramSize, name) {
       var helper = this.setupHelper(paramSize, name);
-      this.pushStack(helper.name + ".call(" + helper.callParams + ")");
+      this.push(helper.name + ".call(" + helper.callParams + ")");
     },
 
     // [invokeAmbiguous]
@@ -1609,19 +1721,18 @@ Handlebars.JavaScriptCompiler = function() {};
     // This operation emits more code than the other options,
     // and can be avoided by passing the `knownHelpers` and
     // `knownHelpersOnly` flags at compile-time.
-    invokeAmbiguous: function(name) {
+    invokeAmbiguous: function(name, helperCall) {
       this.context.aliases.functionType = '"function"';
 
-      this.pushStackLiteral('{}');
-      var helper = this.setupHelper(0, name);
+      this.pushStackLiteral('{}');    // Hash value
+      var helper = this.setupHelper(0, name, helperCall);
 
       var helperName = this.lastHelper = this.nameLookup('helpers', name, 'helper');
-      this.register('foundHelper', helperName);
 
       var nonHelper = this.nameLookup('depth' + this.lastContext, name, 'context');
       var nextStack = this.nextStack();
 
-      this.source.push('if (foundHelper) { ' + nextStack + ' = foundHelper.call(' + helper.callParams + '); }');
+      this.source.push('if (' + nextStack + ' = ' + helperName + ') { ' + nextStack + ' = ' + nextStack + '.call(' + helper.callParams + '); }');
       this.source.push('else { ' + nextStack + ' = ' + nonHelper + '; ' + nextStack + ' = typeof ' + nextStack + ' === functionType ? ' + nextStack + '.apply(depth0) : ' + nextStack + '; }');
     },
 
@@ -1640,7 +1751,7 @@ Handlebars.JavaScriptCompiler = function() {};
       }
 
       this.context.aliases.self = "this";
-      this.pushStack("self.invokePartial(" + params.join(", ") + ")");
+      this.push("self.invokePartial(" + params.join(", ") + ")");
     },
 
     // [assignToHash]
@@ -1651,17 +1762,19 @@ Handlebars.JavaScriptCompiler = function() {};
     // Pops a value and hash off the stack, assigns `hash[key] = value`
     // and pushes the hash back onto the stack.
     assignToHash: function(key) {
-      var value = this.popStack();
+      var value = this.popStack(),
+          type;
 
       if (this.options.stringParams) {
-        var type = this.popStack();
+        type = this.popStack();
         this.popStack();
-        this.source.push("hashTypes['" + key + "'] = " + type + ";");
       }
 
-      var hash = this.topStack();
-
-      this.source.push(hash + "['" + key + "'] = " + value + ";");
+      var hash = this.hash;
+      if (type) {
+        hash.types.push("'" + key + "': " + type);
+      }
+      hash.values.push("'" + key + "': (" + value + ")");
     },
 
     // HELPERS
@@ -1675,11 +1788,27 @@ Handlebars.JavaScriptCompiler = function() {};
         child = children[i];
         compiler = new this.compiler();
 
-        this.context.programs.push('');     // Placeholder to prevent name conflicts for nested children
-        var index = this.context.programs.length;
-        child.index = index;
-        child.name = 'program' + index;
-        this.context.programs[index] = compiler.compile(child, options, this.context);
+        var index = this.matchExistingProgram(child);
+
+        if (index == null) {
+          this.context.programs.push('');     // Placeholder to prevent name conflicts for nested children
+          index = this.context.programs.length;
+          child.index = index;
+          child.name = 'program' + index;
+          this.context.programs[index] = compiler.compile(child, options, this.context);
+          this.context.environments[index] = child;
+        } else {
+          child.index = index;
+          child.name = 'program' + index;
+        }
+      }
+    },
+    matchExistingProgram: function(child) {
+      for (var i = 0, len = this.context.environments.length; i < len; i++) {
+        var environment = this.context.environments[i];
+        if (environment && environment.equals(child)) {
+          return i;
+        }
       }
     },
 
@@ -1723,57 +1852,111 @@ Handlebars.JavaScriptCompiler = function() {};
     },
 
     pushStackLiteral: function(item) {
-      this.compileStack.push(new Literal(item));
-      return item;
+      return this.push(new Literal(item));
     },
 
     pushStack: function(item) {
+      this.flushInline();
+
       var stack = this.incrStack();
-      this.source.push(stack + " = " + item + ";");
+      if (item) {
+        this.source.push(stack + " = " + item + ";");
+      }
       this.compileStack.push(stack);
       return stack;
     },
 
     replaceStack: function(callback) {
-      var stack = this.topStack(),
-          item = callback.call(this, stack);
+      var prefix = '',
+          inline = this.isInline(),
+          stack;
 
-      // Prevent modification of the context depth variable. Through replaceStack
-      if (/^depth/.test(stack)) {
-        stack = this.nextStack();
+      // If we are currently inline then we want to merge the inline statement into the
+      // replacement statement via ','
+      if (inline) {
+        var top = this.popStack(true);
+
+        if (top instanceof Literal) {
+          // Literals do not need to be inlined
+          stack = top.value;
+        } else {
+          // Get or create the current stack name for use by the inline
+          var name = this.stackSlot ? this.topStackName() : this.incrStack();
+
+          prefix = '(' + this.push(name) + ' = ' + top + '),';
+          stack = this.topStack();
+        }
+      } else {
+        stack = this.topStack();
       }
 
-      this.source.push(stack + " = " + item + ";");
+      var item = callback.call(this, stack);
+
+      if (inline) {
+        if (this.inlineStack.length || this.compileStack.length) {
+          this.popStack();
+        }
+        this.push('(' + prefix + item + ')');
+      } else {
+        // Prevent modification of the context depth variable. Through replaceStack
+        if (!/^stack/.test(stack)) {
+          stack = this.nextStack();
+        }
+
+        this.source.push(stack + " = (" + prefix + item + ");");
+      }
       return stack;
     },
 
-    nextStack: function(skipCompileStack) {
-      var name = this.incrStack();
-      this.compileStack.push(name);
-      return name;
+    nextStack: function() {
+      return this.pushStack();
     },
 
     incrStack: function() {
       this.stackSlot++;
       if(this.stackSlot > this.stackVars.length) { this.stackVars.push("stack" + this.stackSlot); }
+      return this.topStackName();
+    },
+    topStackName: function() {
       return "stack" + this.stackSlot;
     },
+    flushInline: function() {
+      var inlineStack = this.inlineStack;
+      if (inlineStack.length) {
+        this.inlineStack = [];
+        for (var i = 0, len = inlineStack.length; i < len; i++) {
+          var entry = inlineStack[i];
+          if (entry instanceof Literal) {
+            this.compileStack.push(entry);
+          } else {
+            this.pushStack(entry);
+          }
+        }
+      }
+    },
+    isInline: function() {
+      return this.inlineStack.length;
+    },
 
-    popStack: function() {
-      var item = this.compileStack.pop();
+    popStack: function(wrapped) {
+      var inline = this.isInline(),
+          item = (inline ? this.inlineStack : this.compileStack).pop();
 
-      if (item instanceof Literal) {
+      if (!wrapped && (item instanceof Literal)) {
         return item.value;
       } else {
-        this.stackSlot--;
+        if (!inline) {
+          this.stackSlot--;
+        }
         return item;
       }
     },
 
-    topStack: function() {
-      var item = this.compileStack[this.compileStack.length - 1];
+    topStack: function(wrapped) {
+      var stack = (this.isInline() ? this.inlineStack : this.compileStack),
+          item = stack[stack.length - 1];
 
-      if (item instanceof Literal) {
+      if (!wrapped && (item instanceof Literal)) {
         return item.value;
       } else {
         return item;
@@ -1788,22 +1971,22 @@ Handlebars.JavaScriptCompiler = function() {};
         .replace(/\r/g, '\\r') + '"';
     },
 
-    setupHelper: function(paramSize, name) {
+    setupHelper: function(paramSize, name, missingParams) {
       var params = [];
-      this.setupParams(paramSize, params);
+      this.setupParams(paramSize, params, missingParams);
       var foundHelper = this.nameLookup('helpers', name, 'helper');
 
       return {
         params: params,
         name: foundHelper,
         callParams: ["depth0"].concat(params).join(", "),
-        helperMissingParams: ["depth0", this.quotedString(name)].concat(params).join(", ")
+        helperMissingParams: missingParams && ["depth0", this.quotedString(name)].concat(params).join(", ")
       };
     },
 
     // the params and contexts arguments are passed in arrays
     // to fill in
-    setupParams: function(paramSize, params) {
+    setupParams: function(paramSize, params, useRegister) {
       var options = [], contexts = [], types = [], param, inverse, program;
 
       options.push("hash:" + this.popStack());
@@ -1848,7 +2031,13 @@ Handlebars.JavaScriptCompiler = function() {};
         options.push("data:data");
       }
 
-      params.push("{" + options.join(",") + "}");
+      options = "{" + options.join(",") + "}";
+      if (useRegister) {
+        this.register('options', options);
+        params.push('options');
+      } else {
+        params.push(options);
+      }
       return params.join(", ");
     }
   };
@@ -1886,23 +2075,23 @@ Handlebars.JavaScriptCompiler = function() {};
 
 })(Handlebars.Compiler, Handlebars.JavaScriptCompiler);
 
-Handlebars.precompile = function(string, options) {
-  if (typeof string !== 'string') {
-    throw new Handlebars.Exception("You must pass a string to Handlebars.compile. You passed " + string);
+Handlebars.precompile = function(input, options) {
+  if (!input || (typeof input !== 'string' && input.constructor !== Handlebars.AST.ProgramNode)) {
+    throw new Handlebars.Exception("You must pass a string or Handlebars AST to Handlebars.compile. You passed " + input);
   }
 
   options = options || {};
   if (!('data' in options)) {
     options.data = true;
   }
-  var ast = Handlebars.parse(string);
+  var ast = Handlebars.parse(input);
   var environment = new Handlebars.Compiler().compile(ast, options);
   return new Handlebars.JavaScriptCompiler().compile(environment, options);
 };
 
-Handlebars.compile = function(string, options) {
-  if (typeof string !== 'string') {
-    throw new Handlebars.Exception("You must pass a string to Handlebars.compile. You passed " + string);
+Handlebars.compile = function(input, options) {
+  if (!input || (typeof input !== 'string' && input.constructor !== Handlebars.AST.ProgramNode)) {
+    throw new Handlebars.Exception("You must pass a string or Handlebars AST to Handlebars.compile. You passed " + input);
   }
 
   options = options || {};
@@ -1911,7 +2100,7 @@ Handlebars.compile = function(string, options) {
   }
   var compiled;
   function compile() {
-    var ast = Handlebars.parse(string);
+    var ast = Handlebars.parse(input);
     var environment = new Handlebars.Compiler().compile(ast, options);
     var templateSpec = new Handlebars.JavaScriptCompiler().compile(environment, options, undefined, true);
     return Handlebars.template(templateSpec);
@@ -1946,12 +2135,32 @@ Handlebars.VM = {
         }
       },
       programWithDepth: Handlebars.VM.programWithDepth,
-      noop: Handlebars.VM.noop
+      noop: Handlebars.VM.noop,
+      compilerInfo: null
     };
 
     return function(context, options) {
       options = options || {};
-      return templateSpec.call(container, Handlebars, context, options.helpers, options.partials, options.data);
+      var result = templateSpec.call(container, Handlebars, context, options.helpers, options.partials, options.data);
+
+      var compilerInfo = container.compilerInfo || [],
+          compilerRevision = compilerInfo[0] || 1,
+          currentRevision = Handlebars.COMPILER_REVISION;
+
+      if (compilerRevision !== currentRevision) {
+        if (compilerRevision < currentRevision) {
+          var runtimeVersions = Handlebars.REVISION_CHANGES[currentRevision],
+              compilerVersions = Handlebars.REVISION_CHANGES[compilerRevision];
+          throw "Template was precompiled with an older version of Handlebars than the current runtime. "+
+                "Please update your precompiler to a newer version ("+runtimeVersions+") or downgrade your runtime to an older version ("+compilerVersions+").";
+        } else {
+          // Use the embedded version info since the runtime doesn't know about this revision yet
+          throw "Template was precompiled with a newer version of Handlebars than the current runtime. "+
+                "Please update your runtime to a newer version ("+compilerInfo[1]+").";
+        }
+      }
+
+      return result;
     };
   },