diff --git a/common/content/dactyl.js b/common/content/dactyl.js
index 1ea54a8d..fe375905 100644
--- a/common/content/dactyl.js
+++ b/common/content/dactyl.js
@@ -25,16 +25,16 @@ const FailedAssertion = Class("FailedAssertion", Error, {
     }
 });
 
-deprecated.seen = { "chrome://dactyl/content/javascript.js": true };
-function deprecated(reason, fn)
+function deprecated(reason, fn) update(
     function deprecatedMethod() {
         let frame = Components.stack.caller;
-        if (!set.add(deprecated.seen, frame.filename))
+        if (!set.add(deprecatedMethod.seen, frame.filename))
             dactyl.echoerr(frame.filename + ":" + frame.lineNumber + ": " +
                 (this.className || this.constructor.className) + "." + fn.name +
                 " is deprecated: " + reason);
         return fn.apply(this, arguments);
-    }
+    },
+    { seen: { "chrome://dactyl/content/javascript.js": true } });
 
 const Dactyl = Module("dactyl", {
     init: function () {
diff --git a/common/content/io.js b/common/content/io.js
index 6660ecac..efab3aa7 100644
--- a/common/content/io.js
+++ b/common/content/io.js
@@ -345,13 +345,15 @@ lookup:
                         dactyl.helpInitialized = false;
                     }
                     catch (e) {
-                        if (isString(e))
-                            e = { message: e };
-                        let err = new Error();
-                        for (let [k, v] in Iterator(e))
-                            err[k] = v;
-                        err.echoerr = <>{file.path}:{e.lineNumber}: {e}</>;
-                        throw err;
+                        if (e.fileName)
+                            try {
+                                e.fileName = e.fileName.replace(/^(chrome|resource):.*? -> /, "");
+                                if (e.fileName == uri.spec)
+                                    e.fileName = filename;
+                                e.echoerr = <>{e.fileName}:{e.lineNumber}: {e}</>
+                            }
+                            catch (e) {}
+                        throw e;
                     }
                 }
                 else if (/\.css$/.test(filename))
diff --git a/common/content/javascript.js b/common/content/javascript.js
index c5c6cd19..c0d30380 100644
--- a/common/content/javascript.js
+++ b/common/content/javascript.js
@@ -358,8 +358,6 @@ const JavaScript = Module("javascript", {
         }
 
         let args = {
-            completer: compl,
-            anchored: true,
             filter: last == null ? key : string,
             last: last,
             prefix: last != null ? key : ""
@@ -369,39 +367,42 @@ const JavaScript = Module("javascript", {
         // TODO: Make this a generic completion helper function.
         for (let [, obj] in Iterator(objects))
             this.context.fork(obj[1], this._top.offset, this, this._fill,
-                update({}, args, {
+                update({
                     obj: obj[0],
-                    name: obj[1]
-                }));
+                    name: obj[1],
+                    anchored: true,
+                    completer: compl
+                }, args));
 
         if (orig)
             return;
 
         for (let [, obj] in Iterator(objects))
             this.context.fork(obj[1] + "/prototypes", this._top.offset, this, this._fill,
-                update({}, args, {
+                update({
                     obj: obj[0],
                     name: obj[1] + " (prototypes)",
+                    anchored: true,
                     completer: function (a, b) compl(a, b, true)
-                }));
+                }, args));
 
         for (let [, obj] in Iterator(objects))
             this.context.fork(obj[1] + "/substrings", this._top.offset, this, this._fill,
-                update({}, args, {
+                update({
                     obj: obj[0],
                     name: obj[1] + " (substrings)",
                     anchored: false,
                     completer: compl
-                }));
+                }, args));
 
         for (let [, obj] in Iterator(objects))
             this.context.fork(obj[1] + "/prototypes/substrings", this._top.offset, this, this._fill,
-                update({}, args, {
+                update({
                     obj: obj[0],
                     name: obj[1] + " (prototype substrings)",
                     anchored: false,
                     completer: function (a, b) compl(a, b, true)
-                }));
+                }, args));
     },
 
     _getKey: function () {
diff --git a/common/modules/base.jsm b/common/modules/base.jsm
index 33635641..9b360ba8 100644
--- a/common/modules/base.jsm
+++ b/common/modules/base.jsm
@@ -10,6 +10,11 @@ const Cr = Components.results;
 const Cu = Components.utils;
 
 Cu.import("resource://gre/modules/XPCOMUtils.jsm");
+try {
+    var ctypes;
+    Components.utils.import("resource://gre/modules/ctypes.jsm");
+}
+catch (e) {}
 
 let objproto = Object.prototype;
 let hasOwnProperty = objproto.hasOwnProperty;
@@ -149,7 +154,7 @@ defineModule("base", {
     exports: [
         "Cc", "Ci", "Class", "Cr", "Cu", "Module", "Object", "Runnable",
         "Struct", "StructBase", "Timer", "UTF8", "XPCOM", "XPCOMUtils", "array",
-        "call", "callable", "curry", "debuggerProperties", "defineModule",
+        "call", "callable", "ctypes", "curry", "debuggerProperties", "defineModule",
         "endModule", "forEach", "isArray", "isGenerator", "isinstance",
         "isObject", "isString", "isSubclass", "iter", "iterAll", "keys",
         "memoize", "properties", "requiresMainThread", "set", "update", "values"
@@ -356,6 +361,20 @@ set.remove = function (set, key) {
  * @returns {Generator}
  */
 function iter(obj) {
+    if (ctypes && obj instanceof ctypes.CData) {
+        while (obj.constructor instanceof ctypes.PointerType)
+            obj = obj.contents;
+        if (obj.constructor instanceof ctypes.ArrayType)
+            return array.iterItems(obj);
+        if (obj.constructor instanceof ctypes.StructType)
+            return (function () {
+                for (let prop in values(obj.constructor.fields))
+                    let ([name, type] = Iterator(prop).next()) {
+                        yield [name, obj[name]];
+                    }
+            })();
+        obj = {};
+    }
     if (isinstance(obj, [Ci.nsIDOMHTMLCollection, Ci.nsIDOMNodeList]))
         return array.iterItems(obj);
     if (obj instanceof Ci.nsIDOMNamedNodeMap)