diff --git a/js/App.js b/js/App.js
index d9372e285..066bc2aad 100644
--- a/js/App.js
+++ b/js/App.js
@@ -14,7 +14,7 @@ var WikiStore = require("./WikiStore.js").WikiStore,
 	tiddlerInput = require("./TiddlerInput.js"),
 	tiddlerOutput = require("./TiddlerOutput.js"),
 	WikiTextProcessor = require("./WikiTextProcessor.js").WikiTextProcessor,
-	Sandbox = require("./Sandbox.js").Sandbox,
+	JavaScriptParser = require("./JavaScriptParser.js").JavaScriptParser,
 	Navigators = require("./Navigators.js").Navigators,
 	StoryNavigator = require("./StoryNavigator.js").StoryNavigator;
 
@@ -73,11 +73,11 @@ var App = function() {
 			this.store.addTiddler(new Tiddler(tiddlers[t]));
 		}
 	}
-	// Set up the sandbox for JavaScript parsing
+	// Set up the JavaScript parser
 	if(this.isBrowser) {
-		this.store.sandbox = new Sandbox(this.store.getTiddlerText("javascript.pegjs"));
+		this.store.jsParser = new JavaScriptParser(this.store.getTiddlerText("javascript.pegjs"));
 	} else {
-		this.store.sandbox = new Sandbox(require("fs").readFileSync("parsers/javascript.pegjs","utf8"));
+		this.store.jsParser = new JavaScriptParser(require("fs").readFileSync("parsers/javascript.pegjs","utf8"));
 	}
 	// Hack to install standard macros
 	this.store.installMacros();
diff --git a/js/JavaScriptParseTree.js b/js/JavaScriptParseTree.js
new file mode 100644
index 000000000..3fa65a273
--- /dev/null
+++ b/js/JavaScriptParseTree.js
@@ -0,0 +1,135 @@
+/*\
+title: js/JavaScriptParseTree.js
+
+JavaScript parse tree
+
+\*/
+(function(){
+
+/*jslint node: true */
+"use strict";
+
+var utils = require("./Utils.js");
+
+// Create a new JavaScript tree object
+var JavaScriptParseTree = function(tree,processor) {
+	this.tree = tree;
+	this.processor = processor;
+};
+
+// Render the entire JavaScript tree object to JavaScript source code
+JavaScriptParseTree.prototype.render = function() {
+	this.output = [];
+	this.renderSubTree(this.tree);
+	return this.output.join("");
+};
+
+JavaScriptParseTree.prototype.renderSubTree = function(tree) {
+	for(var t=0; t<tree.length; t++) {
+		if(t) {
+			this.output.push(";\n");
+		}
+		this.renderNode(tree[t]);
+	}
+};
+
+// Compile a javascript tree into an array of string fragments
+JavaScriptParseTree.prototype.renderNode = function(node) {
+	var p;
+	switch(node.type) {
+		case "StringLiteral":
+			this.output.push(utils.stringify(node.value));
+			break;
+		case "StringLiterals":
+			this.output.push(utils.stringify(node.value.join("")));
+			break;
+		case "FunctionCall":
+			this.output.push("(");
+			this.renderNode(node.name);
+			this.output.push(")(");
+			for(p=0; p<node["arguments"].length; p++) {
+				if(p) {
+					this.output.push(",");
+				}
+				this.renderNode(node["arguments"][p]);
+			}
+			this.output.push(")");
+			break;
+		case "PropertyAccess":
+			this.renderNode(node.base);
+			if(typeof node.name === "string") {
+				this.output.push("." + node.name);
+			} else {
+				this.output.push("[");
+				this.renderNode(node.name);
+				this.output.push("]");	
+			}
+			break;
+		case "ArrayLiteral":
+			this.output.push("[");
+			for(p=0; p<node.elements.length; p++) {
+				if(p) {
+					this.output.push(",");
+				}
+				this.renderNode(node.elements[p]);
+			}
+			this.output.push("]");
+			break;
+		case "Variable":
+			this.output.push(node.name);
+			break;
+		case "ObjectLiteral":
+			this.output.push("{");
+			for(p=0; p<node.properties.length; p++) {
+				if(p) {
+					this.output.push(",");
+				}
+				this.renderNode(node.properties[p]);
+			}
+			this.output.push("}");
+			break;
+		case "PropertyAssignment":
+			this.output.push(node.name);
+			this.output.push(":");
+			this.renderNode(node.value);
+			break;
+		case "BinaryExpression":
+			this.output.push("(");
+			this.renderNode(node.left);
+			this.output.push(")");
+			this.output.push(node.operator);
+			this.output.push("(");
+			this.renderNode(node.right);
+			this.output.push(")");
+			break;
+		case "NumericLiteral":
+			this.output.push(node.value);
+			break;
+		case "Function":
+			this.output.push("(function ");
+			if(node.name !== null) {
+				this.output.push(node.name);
+			}
+			this.output.push("(");
+			this.output.push(node.params.join(","));
+			this.output.push("){");
+			this.renderSubTree(node.elements);
+			this.output.push("})");
+			break;
+		case "ReturnStatement":
+			this.output.push("return ");
+			this.renderNode(node.value);
+			break;
+		case "This":
+			this.output.push("this");
+			break;
+		default:
+			console.log(node);
+			throw "Unknown JavaScript node type: " + node.type;
+			//break;
+	}
+};
+
+exports.JavaScriptParseTree = JavaScriptParseTree;
+
+})();
diff --git a/js/JavaScriptParser.js b/js/JavaScriptParser.js
new file mode 100644
index 000000000..22c1f3cba
--- /dev/null
+++ b/js/JavaScriptParser.js
@@ -0,0 +1,29 @@
+/*\
+title: js/JavaScriptParser.js
+
+JavaScript processing
+
+\*/
+(function(){
+
+/*jslint node: true */
+"use strict";
+
+var JavaScriptParseTree = require("./JavaScriptParseTree.js").JavaScriptParseTree,
+	pegjs = require("pegjs");
+
+var JavaScriptParser = function(parserText) {
+	this.parser = pegjs.buildParser(parserText);
+};
+
+JavaScriptParser.prototype.parse = function(code) {
+	return new JavaScriptParseTree(this.parser.parse(code),this);
+};
+
+JavaScriptParser.prototype.createTree = function(tree) {
+	return new JavaScriptParseTree(tree,this);
+};
+
+exports.JavaScriptParser = JavaScriptParser;
+
+})();
diff --git a/js/Sandbox.js b/js/Sandbox.js
deleted file mode 100644
index 8f9fb8e10..000000000
--- a/js/Sandbox.js
+++ /dev/null
@@ -1,24 +0,0 @@
-/*\
-title: js/Sandbox.js
-
-Execute a fragment of JavaScript in a sandbox
-
-\*/
-(function(){
-
-/*jslint evil: true, node: true */
-"use strict";
-
-var pegjs = require("pegjs");
-
-var Sandbox = function(parserText) {
-	this.parser = pegjs.buildParser(parserText);
-};
-
-Sandbox.prototype.parse = function(code) {
-	return this.parser.parse(code);
-};
-
-exports.Sandbox = Sandbox;
-
-})();
\ No newline at end of file
diff --git a/js/WikiStore.js b/js/WikiStore.js
index ab55976c2..957d84aca 100755
--- a/js/WikiStore.js
+++ b/js/WikiStore.js
@@ -307,8 +307,8 @@ WikiStore.prototype.installMacros = function() {
 				text: {byPos: 0, type: "text", optional: false}
 			},
 			code: {
-				"text/html": this.sandbox.parse("return utils.htmlEncode(params.text);"),
-				"text/plain": this.sandbox.parse("return params.text;")
+				"text/html": this.jsParser.parse("return utils.htmlEncode(params.text);"),
+				"text/plain": this.jsParser.parse("return params.text;")
 			}
 		},
 		view: {
@@ -318,8 +318,8 @@ WikiStore.prototype.installMacros = function() {
 				template: {byPos: 2, type: "text", optional: true}
 			},
 			code: {
-				"text/html": this.sandbox.parse("return store.getFormattedTiddlerField(tiddler.fields.title,params.field,params.format,params.template);"),
-				"text/plain": this.sandbox.parse("return store.getFormattedTiddlerField(tiddler.fields.title,params.field,params.format,params.template);")
+				"text/html": this.jsParser.parse("return store.getFormattedTiddlerField(tiddler.fields.title,params.field,params.format,params.template);"),
+				"text/plain": this.jsParser.parse("return store.getFormattedTiddlerField(tiddler.fields.title,params.field,params.format,params.template);")
 			}
 		},
 		list: {
@@ -329,26 +329,26 @@ WikiStore.prototype.installMacros = function() {
 				emptyMessage: {byName: true, type: "text", optional: true}
 			},
 			code: {
-				"text/html": this.sandbox.parse("return store.listTiddlers(params.type,params.template,params.emptyMessage);"),
-				"text/plain": this.sandbox.parse("return store.listTiddlers(params.type,params.template,params.emptyMessage);")
+				"text/html": this.jsParser.parse("return store.listTiddlers(params.type,params.template,params.emptyMessage);"),
+				"text/plain": this.jsParser.parse("return store.listTiddlers(params.type,params.template,params.emptyMessage);")
 			}
 		},
 		version: {
 			params: {
 			},
 			code: {
-				"text/html": this.sandbox.parse("return '5.0.0';"),
-				"text/plain": this.sandbox.parse("return '5.0.0';")
+				"text/html": this.jsParser.parse("return '5.0.0';"),
+				"text/plain": this.jsParser.parse("return '5.0.0';")
 			}
 		},
 		tiddler: {
 			params: {
 				target: {byName: "default", type: "tiddler", optional: false},
-				with: {byName: true, type: "text", optional: true, cascade: true}
+				"with": {byName: true, type: "text", optional: true, cascade: true}
 			},
 			code: {
-				"text/html": this.sandbox.parse("return store.renderTiddler('text/html',params.target);"),
-				"text/plain": this.sandbox.parse("return store.renderTiddler('text/plain',params.target);")
+				"text/html": this.jsParser.parse("return store.renderTiddler('text/html',params.target);"),
+				"text/plain": this.jsParser.parse("return store.renderTiddler('text/plain',params.target);")
 			}
 		}
 	};
diff --git a/js/WikiTextCompiler.js b/js/WikiTextCompiler.js
index a426efc46..9fa86e15d 100644
--- a/js/WikiTextCompiler.js
+++ b/js/WikiTextCompiler.js
@@ -8,6 +8,7 @@ title: js/WikiTextCompiler.js
 "use strict";
 
 var ArgParser = require("./ArgParser.js").ArgParser,
+	JavaScriptParseTree = require("./JavaScriptParseTree.js").JavaScriptParseTree,
 	utils = require("./Utils.js"),
 	util = require("util");
 
@@ -17,121 +18,6 @@ var WikiTextCompiler = function(store,title,parser) {
 	this.title = title;
 };
 
-// Compile a javascript tree into an array of string fragments
-var compileJavaScript = function(tree) {
-	var output = [],
-		compileJavaScriptTree,
-		compileJavaScriptNode = function(node) {
-		var p;
-		switch(node.type) {
-			case "StringLiteral":
-				output.push(utils.stringify(node.value));
-				break;
-			case "StringLiterals":
-				output.push(utils.stringify(node.value.join("")));
-				break;
-			case "FunctionCall":
-				output.push("(");
-				compileJavaScriptNode(node.name);
-				output.push(")");
-				output.push("(");
-				for(p=0; p<node["arguments"].length; p++) {
-					if(p) {
-						output.push(",");
-					}
-					compileJavaScriptNode(node["arguments"][p]);
-				}
-				output.push(")");
-				break;
-			case "PropertyAccess":
-				compileJavaScriptNode(node.base);
-				if(typeof node.name === "string") {
-					output.push("." + node.name);
-				} else {
-					output.push("[");
-					compileJavaScriptNode(node.name);
-					output.push("]");	
-				}
-				break;
-			case "ArrayLiteral":
-				output.push("[");
-				for(p=0; p<node.elements.length; p++) {
-					if(p) {
-						output.push(",");
-					}
-					compileJavaScriptNode(node.elements[p]);
-				}
-				output.push("]");
-				break;
-			case "Variable":
-				output.push(node.name);
-				break;
-			case "ObjectLiteral":
-				output.push("{");
-				for(p=0; p<node.properties.length; p++) {
-					if(p) {
-						output.push(",");
-					}
-					compileJavaScriptNode(node.properties[p]);
-				}
-				output.push("}");
-				break;
-			case "PropertyAssignment":
-				output.push(node.name);
-				output.push(":");
-				compileJavaScriptNode(node.value);
-				break;
-			case "BinaryExpression":
-				output.push("(");
-				compileJavaScriptNode(node.left);
-				output.push(")");
-				output.push(node.operator);
-				output.push("(");
-				compileJavaScriptNode(node.right);
-				output.push(")");
-				break;
-			case "NumericLiteral":
-				output.push(node.value);
-				break;
-			case "Function":
-				output.push("(");
-				output.push("function ");
-				if(node.name !== null) {
-					output.push(node.name);
-				}
-				output.push("(");
-				output.push(node.params.join(","));
-				output.push(")");
-				output.push("{");
-				compileJavaScriptTree(node.elements);
-				output.push("}");
-				output.push(")");
-				break;
-			case "ReturnStatement":
-				output.push("return ");
-				compileJavaScriptNode(node.value);
-				break;
-			case "This":
-				output.push("this");
-				break;
-			default:
-				console.log(node);
-				throw "Unknown JavaScript node type: " + node.type;
-				//break;
-		}
-	};
-	compileJavaScriptTree = function(tree) {
-		for(var t=0; t<tree.length; t++) {
-			if(t) {
-				output.push(";\n");
-			}
-			compileJavaScriptNode(tree[t]);
-		}
-	};
-	compileJavaScriptTree(tree);
-	return output;
-};
-
 WikiTextCompiler.prototype.compile = function(type,treenode) {
 	if(type === "text/html") {
 		return this.compileAsHtml(treenode);
@@ -193,8 +79,8 @@ WikiTextCompiler.prototype.compileAsHtml = function(treenode) {
 				paramsProps = {};
 			var insertParam = function(name,arg) {
 				if(arg.evaluated) {
-					var prog = me.store.sandbox.parse(arg.string);
-					paramsProps[name] = prog.elements[0];
+					var prog = me.store.jsParser.parse(arg.string);
+					paramsProps[name] = prog.tree.elements[0];
 				} else {
 					paramsProps[name] = {type: "StringLiteral", value: arg.string};
 				}
@@ -225,7 +111,7 @@ WikiTextCompiler.prototype.compileAsHtml = function(treenode) {
 					properties: []	
 				}]
 			};
-			macroCall.name.elements = macro.code["text/html"].elements;
+			macroCall.name.elements = macro.code["text/html"].tree.elements;
 			for(m in paramsProps) {
 				macroCall["arguments"][0].properties.push({
 					type: "PropertyAssignment",
@@ -281,7 +167,7 @@ WikiTextCompiler.prototype.compileAsHtml = function(treenode) {
 	// Compile the wiki parse tree into a javascript parse tree
 	compileSubTree(treenode);
 	// And then render the javascript parse tree back into JavaScript code
-	return compileJavaScript(
+	var parseTree = this.store.jsParser.createTree(
 		[
 			{
 				type: "Function",
@@ -309,8 +195,8 @@ WikiTextCompiler.prototype.compileAsHtml = function(treenode) {
 					}
 				]
 			}
-		]
-	).join("");
+		]);
+	return parseTree.render();
 };
 
 WikiTextCompiler.prototype.compileAsText = function(treenode) {
@@ -343,8 +229,8 @@ WikiTextCompiler.prototype.compileAsText = function(treenode) {
 				paramsProps = {};
 			var insertParam = function(name,arg) {
 				if(arg.evaluated) {
-					var prog = me.store.sandbox.parse(arg.string);
-					paramsProps[name] = prog.elements[0];
+					var prog = me.store.jsParser.parse(arg.string);
+					paramsProps[name] = prog.tree.elements[0];
 				} else {
 					paramsProps[name] = {type: "StringLiteral", value: arg.string};
 				}
@@ -375,7 +261,7 @@ WikiTextCompiler.prototype.compileAsText = function(treenode) {
 					properties: []	
 				}]
 			};
-			macroCall.name.elements = macro.code["text/plain"].elements;
+			macroCall.name.elements = macro.code["text/plain"].tree.elements;
 			for(m in paramsProps) {
 				macroCall["arguments"][0].properties.push({
 					type: "PropertyAssignment",
@@ -421,7 +307,7 @@ WikiTextCompiler.prototype.compileAsText = function(treenode) {
 	// Compile the wiki parse tree into a javascript parse tree
 	compileSubTree(treenode);
 	// And then render the javascript parse tree back into JavaScript code
-	return compileJavaScript(
+	var parseTree = this.store.jsParser.createTree(
 		[
 			{
 				type: "Function",
@@ -449,8 +335,8 @@ WikiTextCompiler.prototype.compileAsText = function(treenode) {
 					}
 				]
 			}
-		]
-	).join("");
+		]);
+	return parseTree.render();
 };
 
 exports.WikiTextCompiler = WikiTextCompiler;
diff --git a/js/WikiTextParser.js b/js/WikiTextParser.js
index fcdffed26..9efef4a28 100644
--- a/js/WikiTextParser.js
+++ b/js/WikiTextParser.js
@@ -9,8 +9,7 @@ Parses a block of tiddlywiki-format wiki text into a parse tree object.
 /*jslint node: true */
 "use strict";
 
-var WikiTextRenderer = require("./WikiTextRenderer.js").WikiTextRenderer,
-	WikiTextCompiler = require("./WikiTextCompiler.js").WikiTextCompiler,
+var WikiTextCompiler = require("./WikiTextCompiler.js").WikiTextCompiler,
 	utils = require("./Utils.js"),
 	util = require("util");
 
@@ -139,11 +138,6 @@ WikiTextParser.prototype.render = function(type,treenode,store,title) {
 	return fn(tiddler,store,utils);
 };
 
-WikiTextParser.prototype.compile = function(type,treenode,store,title) {
-	var compiler = new WikiTextCompiler(store,title,this);
-	return compiler.compile(type,treenode);
-};
-
 exports.WikiTextParser = WikiTextParser;
 
 })();
diff --git a/js/WikiTextRenderer.js b/js/WikiTextRenderer.js
index c7815a490..3a77755dc 100644
--- a/js/WikiTextRenderer.js
+++ b/js/WikiTextRenderer.js
@@ -135,7 +135,7 @@ WikiTextRenderer.prototype.executeMacro = function(macroNode,title) {
 				globals: {
 					title: title
 				},
-				sandbox: this.store.sandbox
+				sandbox: this.store.jsProcessor
 			};
 			for(var g in macroInfo.argOptions) {
 				argOptions[g] = macroInfo.argOptions[g];
diff --git a/tiddlywiki5/tiddlywiki5.recipe b/tiddlywiki5/tiddlywiki5.recipe
index 3fbd23d0a..ecfae6339 100644
--- a/tiddlywiki5/tiddlywiki5.recipe
+++ b/tiddlywiki5/tiddlywiki5.recipe
@@ -7,7 +7,8 @@ recipe: ../parsers/split.recipe
 
 jslib: ../test/tiddlywiki.2.6.5/source/tiddlywiki/jquery/jquery.js
 
-jsmodule: ../js/Sandbox.js
+jsmodule: ../js/JavaScriptParser.js
+jsmodule: ../js/JavaScriptParseTree.js
 jsmodule: ../js/ArgParser.js
 jsmodule: ../js/FileRetriever.js
 jsmodule: ../js/Utils.js