diff --git a/lib/handlebars/ast.js b/lib/handlebars/ast.js
index ccaef511..a266fe78 100644
--- a/lib/handlebars/ast.js
+++ b/lib/handlebars/ast.js
@@ -11,10 +11,11 @@ var Handlebars = require("handlebars");
     if(inverse) { this.inverse = new Handlebars.AST.ProgramNode(inverse); }
   };
 
-  Handlebars.AST.MustacheNode = function(params, unescaped) {
+  Handlebars.AST.MustacheNode = function(params, hash, unescaped) {
     this.type = "mustache";
     this.id = params[0];
     this.params = params.slice(1);
+    this.hash = hash;
     this.escaped = !unescaped;
   };
 
diff --git a/lib/handlebars/printer.js b/lib/handlebars/printer.js
index 86a67ef7..2da7bccb 100644
--- a/lib/handlebars/printer.js
+++ b/lib/handlebars/printer.js
@@ -73,14 +73,17 @@ Handlebars.PrintVisitor.prototype.inverse = function(block) {
 
 
 Handlebars.PrintVisitor.prototype.mustache = function(mustache) {
-  var params = mustache.params, paramStrings = [];
+  var params = mustache.params, paramStrings = [], hash;
 
   for(var i=0, l=params.length; i<l; i++) {
     paramStrings.push(this.accept(params[i]));
   }
 
   params = "[" + paramStrings.join(", ") + "]";
-  return this.pad("{{ " + this.accept(mustache.id) + " " + params + " }}");
+
+  hash = mustache.hash ? " " + this.accept(mustache.hash) : "";
+
+  return this.pad("{{ " + this.accept(mustache.id) + " " + params + hash + " }}");
 };
 
 Handlebars.PrintVisitor.prototype.partial = function(partial) {
diff --git a/lib/handlebars/vm.js b/lib/handlebars/vm.js
index 1c2b4eef..3fb450b0 100644
--- a/lib/handlebars/vm.js
+++ b/lib/handlebars/vm.js
@@ -19,7 +19,8 @@ Handlebars.JavaScriptCompiler = function() {};
     invokeProgram: 11,
     invokePartial: 12,
     push: 13,
-    invokeInverse: 14
+    invokeInverse: 14,
+    assignToHash: 15
   };
 
   Compiler.MULTI_PARAM_OPCODES = {
@@ -34,7 +35,8 @@ Handlebars.JavaScriptCompiler = function() {};
     invokeProgram: 2,
     invokePartial: 1,
     push: 1,
-    invokeInverse: 1
+    invokeInverse: 1,
+    assignToHash: 1
   };
 
   Compiler.DISASSEMBLE_MAP = {};
@@ -163,6 +165,20 @@ Handlebars.JavaScriptCompiler = function() {};
       this.opcode('append');
     },
 
+    hash: function(hash) {
+      var pairs = hash.pairs, pair, val;
+
+      this.opcode('push', '{}');
+
+      for(var i=0, l=pairs.length; i<l; i++) {
+        pair = pairs[i];
+        val  = pair[1];
+
+        this.accept(val);
+        this.opcode('assignToHash', pair[0]);
+      }
+    },
+
     partial: function(partial) {
       var id = partial.id;
       this.usePartial = true;
@@ -185,6 +201,13 @@ Handlebars.JavaScriptCompiler = function() {};
       var params = mustache.params;
 
       this.pushParams(params);
+
+      if(mustache.hash) {
+        this.hash(mustache.hash);
+      } else {
+        this.opcode('push', '{}');
+      }
+
       this.ID(mustache.id);
 
       this.opcode('invokeMustache', params.length, mustache.id.original);
@@ -466,11 +489,19 @@ Handlebars.JavaScriptCompiler = function() {};
 
       fn = this.popStack();
 
+      var hash = this.popStack();
+
       for(var i=0; i<paramSize; i++) {
         params.push(this.popStack());
       }
 
-      if(this.data) { params.push("data"); }
+      this.register('tmp1', '{hash: ' + hash + '}');
+
+      if(this.data) {
+        this.source.push('tmp1.data = data');
+      }
+
+      params.push('tmp1');
 
       var paramString = params.join(", ");
       var helperMissing = ["context"].concat(this.quotedString(original)).concat(params.slice(1));
@@ -479,7 +510,7 @@ Handlebars.JavaScriptCompiler = function() {};
 
       if(paramSize === 0) {
         // TODO: This case is not listed in the mustache spec. Is it important?
-        this.source.push("if(typeof " + fn + " === 'function') { " + slot + " = " + fn + ".call(" + paramString + "); }");
+        this.source.push("if(typeof " + fn + " === 'function') { " + slot + " = " + fn + ".call(" + paramString + "); } else { " + slot + " = " + fn + "; }");
       } else {
         this.source.push("if(typeof " + fn + " === 'function') { " + slot + " = " + fn + ".call(" + paramString + "); } else { " + slot + " = helpers.helperMissing.call(" + helperMissing + ") }");
       }
@@ -506,8 +537,11 @@ Handlebars.JavaScriptCompiler = function() {};
       blockMissingParams.push(mainProgram, inverse);
 
       if(this.data) {
-        params.push("data");
-        blockMissingParams.push("data");
+        this.register('tmp1', '{data: data}');
+        params.push("tmp1");
+
+        params.push("tmp1");
+        blockMissingParams.push("tmp1");
       }
 
       var nextStack = this.nextStack();
@@ -527,6 +561,13 @@ Handlebars.JavaScriptCompiler = function() {};
       this.pushStack("this.invokePartial(" + this.nameLookup('partials', context, 'partial') + ", '" + context + "', " + this.popStack() + ", helpers, partials);");
     },
 
+    assignToHash: function(key) {
+      var value = this.popStack();
+      var hash = this.topStack();
+
+      this.source.push(hash + "['" + key + "'] = " + value + ";");
+    },
+
     // HELPERS
 
     compiler: JavaScriptCompiler,
diff --git a/spec/parser_spec.rb b/spec/parser_spec.rb
index edcc665a..3c6250ab 100644
--- a/spec/parser_spec.rb
+++ b/spec/parser_spec.rb
@@ -65,8 +65,9 @@ describe "Parser" do
       with_padding { yield }
     end
 
-    def mustache(id, *params)
-      pad("{{ #{id} [#{params.join(", ")}] }}")
+    def mustache(id, params = [], hash = nil)
+      hash = " #{hash}" if hash
+      pad("{{ #{id} [#{params.join(", ")}]#{hash} }}")
     end
 
     def partial(id, context = nil)
@@ -113,29 +114,29 @@ describe "Parser" do
   end
 
   it "parses mustaches with parameters" do
-    ast_for("{{foo bar}}").should == program { mustache id("foo"), id("bar") }
+    ast_for("{{foo bar}}").should == program { mustache id("foo"), [id("bar")] }
   end
 
   it "parses mustaches with hash arguments" do
     ast_for("{{foo bar=baz}}").should == program do
-      mustache id("foo"), hash(["bar", "ID:baz"])
+      mustache id("foo"), [], hash(["bar", "ID:baz"])
     end
 
     ast_for("{{foo bar=baz bat=bam}}").should == program do
-      mustache id("foo"), hash(["bar", "ID:baz"], ["bat", "ID:bam"])
+      mustache id("foo"), [], hash(["bar", "ID:baz"], ["bat", "ID:bam"])
     end
 
     ast_for("{{foo bar=baz bat=\"bam\"}}").should == program do
-      mustache id("foo"), hash(["bar", "ID:baz"], ["bat", "\"bam\""])
+      mustache id("foo"), [], hash(["bar", "ID:baz"], ["bat", "\"bam\""])
     end
 
     ast_for("{{foo omg bar=baz bat=\"bam\"}}").should == program do
-      mustache id("foo"), id("omg"), hash(["bar", id("baz")], ["bat", string("bam")])
+      mustache id("foo"), [id("omg")], hash(["bar", id("baz")], ["bat", string("bam")])
     end
   end
 
   it "parses mustaches with string parameters" do
-    ast_for("{{foo bar \"baz\" }}").should == program { mustache id("foo"), id("bar"), string("baz")}
+    ast_for("{{foo bar \"baz\" }}").should == program { mustache id("foo"), [id("bar"), string("baz")] }
   end
 
   it "parses contents followed by a mustache" do
diff --git a/spec/qunit_spec.js b/spec/qunit_spec.js
index 01c1aba0..e82ffb3f 100644
--- a/spec/qunit_spec.js
+++ b/spec/qunit_spec.js
@@ -420,13 +420,6 @@ test("GH-14: a partial preceding a selector", function() {
    shouldCompileTo(string, [hash, {}, {dude:dude}], "Dudes: Jeepers Creepers", "Regular selectors can follow a partial");
 });
 
-test("Partial containing complex expression", function() {
-	var template = "Dudes: {{#dudes}}{{> dude}} {{/dudes}}";
-	var dude = "{{../salutation}} {{name}}";
-	var hash = {salutation: "Mr.", dudes: [{name: "Yehuda"}, {name: "Alan"}]};
-	shouldCompileTo(template, [hash, {}, {dude: dude}], "Dudes: Mr. Yehuda Mr. Alan ");
-});
-
 module("String literal parameters");
 
 test("simple literals work", function() {
@@ -529,8 +522,8 @@ test("passing in data to a compiled function that expects data - works with help
   var template = Handlebars.compile("{{hello}}", true);
 
   var helpers = {
-    hello: function(data) {
-      return data.adjective + " "  + this.noun;
+    hello: function(options) {
+      return options.data.adjective + " "  + this.noun;
     }
   };
 
@@ -542,8 +535,8 @@ test("passing in data to a compiled function that expects data - works with help
   var template = Handlebars.compile("{{hello world}}", true);
 
   var helpers = {
-    hello: function(noun, data) {
-      return data.adjective + " "  + noun + (this.exclaim ? "!" : "");
+    hello: function(noun, options) {
+      return options.data.adjective + " "  + noun + (this.exclaim ? "!" : "");
     }
   };
 
@@ -558,8 +551,8 @@ test("passing in data to a compiled function that expects data - works with bloc
     hello: function(fn) {
       return fn(this);
     },
-    world: function(data) {
-      return data.adjective + " world" + (this.exclaim ? "!" : "");
+    world: function(options) {
+      return options.data.adjective + " world" + (this.exclaim ? "!" : "");
     }
   };
 
@@ -574,8 +567,8 @@ test("passing in data to a compiled function that expects data - works with bloc
     hello: function(fn) {
       return fn({exclaim: "?"});
     },
-    world: function(thing, data) {
-      return data.adjective + " " + thing + (this.exclaim || "");
+    world: function(thing, options) {
+      return options.data.adjective + " " + thing + (this.exclaim || "");
     }
   };
 
@@ -587,11 +580,11 @@ test("passing in data to a compiled function that expects data - works with bloc
   var template = Handlebars.compile("{{#hello}}{{world ../zomg}}{{/hello}}", true);
 
   var helpers = {
-    hello: function(fn, inverse, data) {
-      return data.accessData + " " + fn({exclaim: "?"});
+    hello: function(fn, inverse, options) {
+      return options.data.accessData + " " + fn({exclaim: "?"});
     },
-    world: function(thing, data) {
-      return data.adjective + " " + thing + (this.exclaim || "");
+    world: function(thing, options) {
+      return options.data.adjective + " " + thing + (this.exclaim || "");
     }
   };
 
@@ -606,8 +599,8 @@ test("you can override inherited data when invoking a helper", function() {
     hello: function(fn) {
       return fn({exclaim: "?", zomg: "world"}, null, null, {adjective: "sad"});
     },
-    world: function(thing, data) {
-      return data.adjective + " " + thing + (this.exclaim || "");
+    world: function(thing, options) {
+      return options.data.adjective + " " + thing + (this.exclaim || "");
     }
   };
 
@@ -623,8 +616,8 @@ test("you can override inherited data when invoking a helper with depth", functi
     hello: function(fn) {
       return fn({exclaim: "?"}, null, null, {adjective: "sad"});
     },
-    world: function(thing, data) {
-      return data.adjective + " " + thing + (this.exclaim || "");
+    world: function(thing, options) {
+      return options.data.adjective + " " + thing + (this.exclaim || "");
     }
   };
 
@@ -676,3 +669,21 @@ test("helpers take precedence over same-named context properties", function() {
   equals(result, "GOODBYE cruel WORLD");
 });
 
+test("helpers can take an optional hash", function() {
+  var template = Handlebars.compile('{{goodbye cruel="CRUEL" world="WORLD"}}');
+
+  var helpers = {
+    goodbye: function(options) {
+      return "GOODBYE " + options.hash.cruel + " " + options.hash.world;
+    }
+  };
+
+  var context = {};
+
+  var result = template(context, helpers);
+  equals(result, "GOODBYE CRUEL WORLD");
+});
+
+// test("helpers can take an optional hash", function() {
+//   var template = Handlebars.compile('{{#goodbye cruel="CRUEL"}}world{{/goodbye}}')
+// });
diff --git a/src/handlebars.yy b/src/handlebars.yy
index e9a0c13c..f119df22 100644
--- a/src/handlebars.yy
+++ b/src/handlebars.yy
@@ -27,11 +27,11 @@ statement
   ;
 
 openBlock
-  : OPEN_BLOCK inMustache CLOSE { $$ = new yy.MustacheNode($2) }
+  : OPEN_BLOCK inMustache CLOSE { $$ = new yy.MustacheNode($2[0], $2[1]) }
   ;
 
 openInverse
-  : OPEN_INVERSE inMustache CLOSE { $$ = new yy.MustacheNode($2) }
+  : OPEN_INVERSE inMustache CLOSE { $$ = new yy.MustacheNode($2[0], $2[1]) }
   ;
 
 closeBlock
@@ -39,8 +39,8 @@ closeBlock
   ;
 
 mustache
-  : OPEN inMustache CLOSE { $$ = new yy.MustacheNode($2) }
-  | OPEN_UNESCAPED inMustache CLOSE { $$ = new yy.MustacheNode($2, true) }
+  : OPEN inMustache CLOSE { $$ = new yy.MustacheNode($2[0], $2[1]) }
+  | OPEN_UNESCAPED inMustache CLOSE { $$ = new yy.MustacheNode($2[0], $2[1], true) }
   ;
 
 
@@ -54,10 +54,10 @@ simpleInverse
   ;
 
 inMustache
-  : path params hash { $$ = [$1].concat($2).concat([$3]) }
-  | path params { $$ = [$1].concat($2) }
-  | path hash { $$ = [$1].concat([$2]) }
-  | path { $$ = [$1] }
+  : path params hash { $$ = [[$1].concat($2), $3] }
+  | path params { $$ = [[$1].concat($2), null] }
+  | path hash { $$ = [[$1], $2] }
+  | path { $$ = [[$1], null] }
   ;
 
 params