diff --git a/common/content/commandline.js b/common/content/commandline.js
index 24c834bb..4b0d104e 100644
--- a/common/content/commandline.js
+++ b/common/content/commandline.js
@@ -1397,8 +1397,8 @@ var CommandLine = Module("commandline", {
             substring = substring.substr(value.length);
             this.removeSubstring = substring;
 
-            let node = DOM.fromXML(<span highlight="Preview">{substring}</span>,
-                                   document);
+            let node = DOM.fromJSON(["span", { highlight: "Preview" }, substring],
+                                    document);
 
             this.withSavedValues(["caret"], function () {
                 this.editor.insertNode(node, this.editor.rootElement, 1);
@@ -1889,19 +1889,18 @@ var ItemList = Class("ItemList", {
         DOM(this.win).resize(this._onResize.closure.tell);
     },
 
-    get rootXML() <e4x>
-        <div highlight="Normal" style="white-space: nowrap" key="root">
-            <div key="wrapper">
-                <div highlight="Completions" key="noCompletions"><span highlight="Title">{_("completion.noCompletions")}</span></div>
-                <div key="completions"/>
-            </div>
+    get rootXML()
+        ["div", { highlight: "Normal", style: "white-space: nowrap", key: "root" },
+            ["div", { key: "wrapper" },
+                ["div", { highlight: "Completions", key: "noCompletions" },
+                    ["span", { highlight: "Title" },
+                        _("completion.noCompletions")]],
+                ["div", { key: "completions" }]],
 
-            <div highlight="Completions">{
-            template.map(util.range(0, options["maxitems"] * 2), function (i)
-                <div highlight="CompItem NonText"><li>~</li></div>)
-            }</div>
-        </div>
-    </e4x>.elements(),
+            ["div", { highlight: "Completions" },
+                template_.map(util.range(0, options["maxitems"] * 2), function (i)
+                    ["div", { highlight: "CompItem NonText" },
+                        "~"])]],
 
     get itemCount() this.context.contextList.reduce(function (acc, ctxt) acc + ctxt.items.length, 0),
 
@@ -2225,21 +2224,19 @@ var ItemList = Class("ItemList", {
         },
 
         get rootXML()
-            <div key="root" highlight="CompGroup">
-                <div highlight="Completions">
-                    { this.context.createRow(this.context.title || [], "CompTitle") }
-                </div>
-                <div highlight="CompTitleSep"/>
-                <div key="contents">
-                    <div key="up" highlight="CompLess"/>
-                    <div key="message" highlight="CompMsg">{this.context.message}</div>
-                    <div key="itemsContainer" class="completion-items-container">
-                        <div key="items" highlight="Completions"/>
-                    </div>
-                    <div key="waiting" highlight="CompMsg">{ItemList.WAITING_MESSAGE}</div>
-                    <div key="down" highlight="CompMore"/>
-                </div>
-            </div>,
+            ["div", { key: "root", highlight: "CompGroup" },
+                ["div", { highlight: "Completions" },
+                    this.context.createRow(this.context.title || [], "CompTitle")],
+                ["div", { highlight: "CompTitleSep" }],
+                ["div", { key: "contents" },
+                    ["div", { key: "up", highlight: "CompLess" }],
+                    ["div", { key: "message", highlight: "CompMsg" },
+                        this.context.message || []],
+                    ["div", { key: "itemsContainer", class: "completion-items-container" },
+                        ["div", { key: "items", highlight: "Completions" }]],
+                    ["div", { key: "waiting", highlight: "CompMsg" },
+                        ItemList.WAITING_MESSAGE],
+                    ["div", { key: "down", highlight: "CompMore" }]]],
 
         get doc() this.parent.doc,
         get win() this.parent.win,
@@ -2281,7 +2278,7 @@ var ItemList = Class("ItemList", {
             this.nodes = {};
             this.generatedRange = ItemList.Range(0, 0);
 
-            DOM.fromXML(this.rootXML, this.doc, this.nodes);
+            DOM.fromJSON(this.rootXML, this.doc, this.nodes);
         },
 
         /**
@@ -2292,7 +2289,8 @@ var ItemList = Class("ItemList", {
             DOM(this.nodes.items).empty();
 
             if (this.context.message)
-                DOM(this.nodes.message).empty().append(<>{this.context.message}</>);
+                DOM(this.nodes.message).empty()
+                    .append(DOM.fromJSON(this.context.message, this.doc));
 
             if (!this.selectedIdx > this.itemCount)
                 this.selectedIdx = null;
diff --git a/common/modules/javascript.jsm b/common/modules/javascript.jsm
index 32af91b9..bf0d9fe3 100644
--- a/common/modules/javascript.jsm
+++ b/common/modules/javascript.jsm
@@ -2,7 +2,7 @@
 //
 // This work is licensed for reuse under an MIT license. Details are
 // given in the LICENSE.txt file included with this file.
-/* use strict */
+"use strict";
 
 let { getOwnPropertyNames } = Object;
 
@@ -13,7 +13,7 @@ defineModule("javascript", {
     require: ["util"]
 });
 
-lazyRequire("template", ["template"]);
+lazyRequire("template", ["template", "template_"]);
 
 let isPrototypeOf = Object.prototype.isPrototypeOf;
 
@@ -489,10 +489,10 @@ var JavaScript = Module("javascript", {
                     if (callable(func)) {
                         let [, prefix, args] = /^(function .*?)\((.*?)\)/.exec(Function.prototype.toString.call(func));
                         let n = this._get(i).comma.length;
-                        args = template.map(Iterator(args.split(", ")),
-                            function ([i, arg]) <span highlight={i == n ? "Filter" : ""}>{arg}</span>,
-                            <>,&#xa0;</>);
-                        this.context.message = <>{prefix}({args})</>;
+                        args = template_.map(Iterator(args.split(", ")),
+                            function ([i, arg]) ["span", { highlight: i == n ? "Filter" : "" }, arg],
+                            ",\u00a0");
+                        this.context.message = ["", prefix + "(", args, ")"];
                     }
                 }
             }
@@ -596,8 +596,8 @@ var JavaScript = Module("javascript", {
         if (!this.context.tabPressed && key == "" && obj.length > 1) {
             let message = this.context.message || "";
             this.context.waitingForTab = true;
-            this.context.message = <>{message}
-                                     {_("completion.waitingForKeyPress")}</>;
+            this.context.message = ["", message, "\n",
+                                    _("completion.waitingForKeyPress")];
             return null;
         }
 
@@ -716,7 +716,6 @@ var JavaScript = Module("javascript", {
             },
 
             addOutput: function addOutput(js) {
-                default xml namespace = XHTML;
                 this.count++;
 
                 try {
@@ -729,19 +728,21 @@ var JavaScript = Module("javascript", {
 
                     if (e.fileName)
                         e = util.fixURI(e.fileName) + ":" + e.lineNumber + ": " + e;
-                    xml = <span highlight="ErrorMsg">{e}</span>;
+                    xml = ["span", { highlight: "ErrorMsg" }, e];
                 }
 
                 let prompt = "js" + this.count;
                 Class.replaceProperty(this.context, prompt, result);
 
-                XML.ignoreWhitespace = XML.prettyPrinting = false;
                 let nodes = {};
                 this.rootNode.appendChild(
-                    util.xmlToDom(<e4x>
-                        <div highlight="REPL-E" key="e"><span highlight="REPL-R">{prompt}></span> {js}</div>
-                        <div highlight="REPL-P" key="p">{xml}</div>
-                    </e4x>.elements(), this.document, nodes));
+                    DOM.fromJSON(
+                        [["div", { highlight: "REPL-E", key: "e" },
+                            ["span", { highlight: "REPL-R" },
+                                prompt, ">"], " ", js],
+                         ["div", { highlight: "REPL-P", key: "p" },
+                            xml]],
+                        this.document, nodes));
 
                 this.rootNode.scrollTop += nodes.e.getBoundingClientRect().top
                                          - this.rootNode.getBoundingClientRect().top;
@@ -750,7 +751,6 @@ var JavaScript = Module("javascript", {
             count: 0,
 
             message: Class.Memoize(function () {
-                default xml namespace = XHTML;
                 DOM.fromJSON(["div", { highlight: "REPL", key: "rootNode" }],
                               this.document, this);
 
diff --git a/common/modules/util.jsm b/common/modules/util.jsm
index 288c30c4..5981ac02 100644
--- a/common/modules/util.jsm
+++ b/common/modules/util.jsm
@@ -1024,7 +1024,7 @@ var Util = Module("Util", XPCOM([Ci.nsIObserver, Ci.nsISupportsWeakReference]),
         return color ? <div style="white-space: pre-wrap;">{string}</div> : [s for each (s in string)].join("");
     },
 
-    prettifyJSON: function prettifyJSON(data, indent) {
+    prettifyJSON: function prettifyJSON(data, indent, invalidOK) {
         const INDENT = indent || "    ";
 
         function rec(data, level, seen) {
@@ -1072,6 +1072,8 @@ var Util = Module("Util", XPCOM([Ci.nsIObserver, Ci.nsISupportsWeakReference]),
                 else
                     res[res.length - 1] = "{}";
             }
+            else if (invalidOK)
+                res.push({}.toString.call(data));
             else
                 throw Error("Invalid JSON object");
         }