diff --git a/lib/handlebars/base.js b/lib/handlebars/base.js
index 583f88c2..63aa1d60 100644
--- a/lib/handlebars/base.js
+++ b/lib/handlebars/base.js
@@ -106,10 +106,11 @@ Handlebars.logger = {
 
   // override in the host environment
   log: function(level, str) {}
-}
+};
 
 Handlebars.log = function(level, str) { Handlebars.logger.log(level, str); };
 
 // END(BROWSER)
 
 module.exports = Handlebars;
+
diff --git a/lib/handlebars/vm.js b/lib/handlebars/vm.js
index 5013b7ae..fee59534 100644
--- a/lib/handlebars/vm.js
+++ b/lib/handlebars/vm.js
@@ -246,8 +246,28 @@ Handlebars.JavaScriptCompiler = function() {};
   };
 
   JavaScriptCompiler.prototype = {
-    compile: function(environment) {
+    // 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) {
+      if(JavaScriptCompiler.RESERVED_WORDS[name]) {
+        return parent + "['" + name + "']";
+      } else {
+        return parent + "." + name;
+      }
+    },
+
+    appendToBuffer: function(string) {
+      return "buffer = buffer + " + string + ";";
+    },
+
+    initializeBuffer: function() {
+      return this.quotedString("");
+    },
+    // END PUBLIC API
+
+    compile: function(environment, data) {
       this.environment = environment;
+      this.data = data;
 
       this.preamble();
 
@@ -255,7 +275,7 @@ Handlebars.JavaScriptCompiler = function() {};
       this.stackVars = [];
       this.registers = {list: []};
 
-      this.compileChildren(environment);
+      this.compileChildren(environment, data);
 
       Handlebars.log(Handlebars.logger.DEBUG, environment.disassemble() + "\n\n");
 
@@ -306,7 +326,7 @@ Handlebars.JavaScriptCompiler = function() {};
 
     preamble: function() {
       var out = [];
-      out.push("var buffer = '', currentContext = context");
+      out.push("var buffer = " + this.initializeBuffer() + ", currentContext = context");
 
       var copies = "helpers = helpers || Handlebars.helpers;";
       if(this.environment.usePartial) { copies = copies + " partials = partials || Handlebars.partials;"; }
@@ -323,9 +343,11 @@ Handlebars.JavaScriptCompiler = function() {};
         escapeExpression: Handlebars.Utils.escapeExpression,
         invokePartial: Handlebars.VM.invokePartial,
         programs: [],
-        program: function(i, helpers, partials) {
+        program: function(i, helpers, partials, data) {
           var programWrapper = this.programs[i];
-          if(programWrapper) {
+          if(data) {
+            return Handlebars.VM.program(this.children[i], helpers, partials, data);
+          } else if(programWrapper) {
             return programWrapper;
           } else {
             programWrapper = this.programs[i] = Handlebars.VM.program(this.children[i], helpers, partials);
@@ -347,11 +369,14 @@ Handlebars.JavaScriptCompiler = function() {};
 
       var params = ["Handlebars", "context", "helpers", "partials"];
 
+      if(this.data) { params.push("data"); }
+
       for(var i=0, l=this.environment.depths.list.length; i<l; i++) {
         params.push("depth" + this.environment.depths.list[i]);
       }
 
-      if(params.length === 3 && !this.environment.usePartial) { params.pop(); }
+
+      if(params.length === 4 && !this.environment.usePartial) { params.pop(); }
 
       params.push(this.source.join("\n"));
 
@@ -364,9 +389,11 @@ Handlebars.JavaScriptCompiler = function() {};
 
       container.children = this.environment.children;
 
-      return function(context, helpers, partials, depth) {
+      return function(context, helpers, partials, data, $depth) {
         try {
-          return container.render.call(container, Handlebars, context, helpers, partials, depth);
+          var args = Array.prototype.slice.call(arguments);
+          args.unshift(Handlebars);
+          return container.render.apply(container, args);
         } catch(e) {
           throw e;
         }
@@ -374,12 +401,12 @@ Handlebars.JavaScriptCompiler = function() {};
     },
 
     appendContent: function(content) {
-      this.source.push("buffer = buffer + " + this.quotedString(content) + ";");
+      this.source.push(this.appendToBuffer(this.quotedString(content)));
     },
 
     append: function() {
       var local = this.popStack();
-      this.source.push("if(" + local + " || " + local + " === 0) { buffer = buffer + " + local + "; }");
+      this.source.push("if(" + local + " || " + local + " === 0) { " + this.appendToBuffer(local) + " }");
     },
 
     appendEscaped: function() {
@@ -390,7 +417,7 @@ Handlebars.JavaScriptCompiler = function() {};
         this.eat(opcode);
       }
 
-      this.source.push("buffer = buffer + this.escapeExpression(" + this.popStack() + ")" + extra + ";");
+      this.source.push(this.appendToBuffer("this.escapeExpression(" + this.popStack() + ")" + extra));
     },
 
     getContext: function(depth) {
@@ -405,19 +432,11 @@ Handlebars.JavaScriptCompiler = function() {};
       }
     },
 
-    nameLookup: function(parent, name) {
-      if(JavaScriptCompiler.RESERVED_WORDS[name]) {
-        return parent + "['" + name + "']";
-      } else {
-        return parent + "." + name;
-      }
-    },
-
     lookupWithFallback: function(name) {
       if(name) {
-        this.pushStack(this.nameLookup('currentContext', name));
+        this.pushStack(this.nameLookup('currentContext', name, 'context'));
         var topStack = this.topStack();
-        this.source.push("if(" + topStack + " === undefined) { " + topStack + " = " + this.nameLookup('helpers', name) + "; }");
+        this.source.push("if(" + topStack + " === undefined) { " + topStack + " = " + this.nameLookup('helpers', name, 'helper') + "; }");
       } else {
         this.pushStack("currentContext");
       }
@@ -425,7 +444,7 @@ Handlebars.JavaScriptCompiler = function() {};
 
     lookup: function(name) {
       var topStack = this.topStack();
-      this.source.push(topStack + " = " + this.nameLookup(topStack, name) + ";");
+      this.source.push(topStack + " = " + this.nameLookup(topStack, name, 'context') + ";");
     },
 
     pushString: function(string) {
@@ -445,6 +464,8 @@ Handlebars.JavaScriptCompiler = function() {};
         params.push(this.popStack());
       }
 
+      if(this.data) { params.push("data"); }
+
       var paramString = params.join(", ");
       var helperMissing = ["context"].concat(this.quotedString(original)).concat(params.slice(1));
 
@@ -492,12 +513,12 @@ Handlebars.JavaScriptCompiler = function() {};
     },
 
     invokePartial: function(context) {
-      this.pushStack("this.invokePartial(" + this.nameLookup('partials', context) + ", '" + context + "', " + this.popStack() + ", helpers, partials);");
+      this.pushStack("this.invokePartial(" + this.nameLookup('partials', context, 'partial') + ", '" + context + "', " + this.popStack() + ", helpers, partials);");
     },
 
     // HELPERS
 
-    compileChildren: function(environment) {
+    compileChildren: function(environment, data) {
       var children = environment.children, child, compiler;
       var compiled = [];
 
@@ -505,7 +526,7 @@ Handlebars.JavaScriptCompiler = function() {};
         child = children[i];
         compiler = new JavaScriptCompiler();
 
-        compiled[i] = compiler.compile(child);
+        compiled[i] = compiler.compile(child, data);
       }
 
       environment.rawChildren = children;
@@ -519,6 +540,8 @@ Handlebars.JavaScriptCompiler = function() {};
 
       var depths = this.environment.rawChildren[guid].depths.list;
 
+      if(this.data) { programParams.push("data"); }
+
       for(var i=0, l = depths.length; i<l; i++) {
         depth = depths[i];
 
@@ -526,7 +549,7 @@ Handlebars.JavaScriptCompiler = function() {};
         else { programParams.push("depth" + (depth - 1)); }
       }
 
-      if(!this.environment.usePartial) { 
+      if(!this.environment.usePartial) {
         if(programParams[3]) {
           programParams[2] = "null";
         } else {
@@ -540,8 +563,6 @@ Handlebars.JavaScriptCompiler = function() {};
         programParams[0] = "this.children[" + guid + "]";
         return "this.programWithDepth(" + programParams.join(", ") + ")";
       }
-
-      return "this.program(" + programParams.join(", ") + ")";
     },
 
     register: function(name, val) {
@@ -597,22 +618,22 @@ Handlebars.JavaScriptCompiler = function() {};
 })(Handlebars.Compiler, Handlebars.JavaScriptCompiler);
 
 Handlebars.VM = {
-  programWithDepth: function(fn, helpers, partials, depth) {
-    var args = [].slice.call(arguments, 1);
+  programWithDepth: function(fn) {
+    var args = Array.prototype.slice.call(arguments, 1);
     return function(context) {
       return fn.apply(this, [context].concat(args));
     };
   },
-  program: function(fn, helpers, partials) {
+  program: function(fn, helpers, partials, data) {
     return function(context) {
-      return fn(context, helpers, partials);
+      return fn(context, helpers, partials, data);
     };
   },
   noop: function() { return ""; },
-  compile: function(string) {
+  compile: function(string, data) {
     var ast = Handlebars.parse(string);
     var environment = new Handlebars.Compiler().compile(ast);
-    return new Handlebars.JavaScriptCompiler().compile(environment);
+    return new Handlebars.JavaScriptCompiler().compile(environment, data);
   },
   invokePartial: function(partial, name, context, helpers, partials) {
     if(partial === undefined) {
diff --git a/spec/qunit_spec.js b/spec/qunit_spec.js
index 30dac7f8..3e5fe8bd 100644
--- a/spec/qunit_spec.js
+++ b/spec/qunit_spec.js
@@ -20,7 +20,7 @@ var shouldCompileTo = function(string, hash, expected, message) {
 
   result = template.apply(this, hash)
   equal(result, expected, "'" + expected + "' should === '" + result + "': " + message);
-}
+};
 
 var shouldThrow = function(fn, exception, message) {
   var caught = false;
@@ -518,4 +518,69 @@ test("each", function() {
                   "each with array argument iterates over the contents when not empty");
   shouldCompileTo(string, {goodbyes: [], world: "world"}, "cruel world!",
                   "each with array argument ignores the contents when empty");
-});
\ No newline at end of file
+});
+
+test("overriding property lookup", function() {
+
+});
+
+
+test("passing in data to a compiled function that expects data - works with helpers", function() {
+  var template = Handlebars.compile("{{hello}}", true);
+
+  var helpers = {
+    hello: function(data) {
+      return data.adjective + " "  + this.noun;
+    }
+  };
+
+  var result = template({noun: "cat"}, helpers, null, {adjective: "happy"});
+  equals("happy cat", result);
+});
+
+test("passing in data to a compiled function that expects data - works with helpers and parameters", function() {
+  var template = Handlebars.compile("{{hello world}}", true);
+
+  var helpers = {
+    hello: function(noun, data) {
+      return data.adjective + " "  + noun + (this.exclaim ? "!" : "");
+    }
+  };
+
+  var result = template({exclaim: true, world: "world"}, helpers, null, {adjective: "happy"});
+  equals("happy world!", result);
+});
+
+test("passing in data to a compiled function that expects data - works with block helpers", function() {
+  var template = Handlebars.compile("{{#hello}}{{world}}{{/hello}}", true);
+
+  var helpers = {
+    hello: function(fn) {
+      return fn(this);
+    },
+    world: function(data) {
+      return data.adjective + " world" + (this.exclaim ? "!" : "");
+    }
+  };
+
+  var result = template({exclaim: true}, helpers, null, {adjective: "happy"});
+  equals("happy world!", result);
+});
+
+test("passing in data to a compiled function that expects data - works with block helpers that use ..", function() {
+  var template = Handlebars.compile("{{#hello}}{{world ../zomg}}{{/hello}}", true);
+
+  var helpers = {
+    hello: function(fn) {
+      return fn({exclaim: "?"});
+    },
+    world: function(thing, data) {
+      return data.adjective + " " + thing + (this.exclaim || "");
+    }
+  };
+
+  var result = template({exclaim: true, zomg: "world"}, helpers, null, {adjective: "happy"});
+  equals("happy world?", result);
+});
+
+
diff --git a/spec/spec_helper.rb b/spec/spec_helper.rb
index 0abfe206..95496cb4 100644
--- a/spec/spec_helper.rb
+++ b/spec/spec_helper.rb
@@ -85,7 +85,7 @@ module Handlebars
       context["Handlebars"]["logger"]["level"] = ENV["DEBUG_JS"] ? context["Handlebars"]["logger"][ENV["DEBUG_JS"]] : 4
 
       context["Handlebars"]["logger"]["log"] = proc do |level, str|
-        logger_level = context["Handlebars"]["logger"]["level"]
+        logger_level = context["Handlebars"]["logger"]["level"].to_i
 
         if logger_level <= level
           puts str