diff --git a/common/content/commandline.js b/common/content/commandline.js
index 8ebe3769..95388bac 100644
--- a/common/content/commandline.js
+++ b/common/content/commandline.js
@@ -1964,7 +1964,7 @@ const ItemList = Class("ItemList", {
         //if (index == 0)
         //    this.start = now;
         //if (index == Math.min(len - 1, 100))
-        //    dactyl.dump({ time: Date.now() - this.start });
+        //    util.dump({ time: Date.now() - this.start });
     },
 
     onEvent: function onEvent(event) false
diff --git a/common/content/dactyl.js b/common/content/dactyl.js
index ce85f822..73853241 100644
--- a/common/content/dactyl.js
+++ b/common/content/dactyl.js
@@ -59,7 +59,7 @@ const Dactyl = Module("dactyl", {
         autocommands.trigger("LeavePre", {});
         storage.saveAll();
         dactyl.triggerObserver("shutdown", null);
-        dactyl.dump("All dactyl modules destroyed\n");
+        util.dump("All dactyl modules destroyed\n");
         autocommands.trigger("Leave", {});
     },
 
@@ -1897,7 +1897,7 @@ const Dactyl = Module("dactyl", {
             dactyl.commandLineOptions.noPlugins = "++noplugin" in args;
             dactyl.commandLineOptions.postCommands = args["+c"];
             dactyl.commandLineOptions.preCommands = args["++cmd"];
-            dactyl.dump("Processing command-line option: " + commandline);
+            util.dump("Processing command-line option: " + commandline);
         }
 
         dactyl.log("Command-line options: " + util.objectToString(dactyl.commandLineOptions), 3);
diff --git a/common/content/events.js b/common/content/events.js
index ea8b2a06..d0cee8b6 100644
--- a/common/content/events.js
+++ b/common/content/events.js
@@ -88,7 +88,7 @@ const Events = Module("events", {
     },
 
     destroy: function () {
-        dactyl.dump("Removing all event listeners");
+        util.dump("Removing all event listeners");
         for (let args in values(this.sessionListeners))
             args[0].removeEventListener.apply(args[0], args.slice(1));
     },
@@ -571,7 +571,7 @@ const Events = Module("events", {
      * @returns {boolean}
      */
     waitForPageLoad: function () {
-        //dactyl.dump("start waiting in loaded state: " + buffer.loaded);
+        //util.dump("start waiting in loaded state: " + buffer.loaded);
         util.threadYield(true); // clear queue
 
         if (buffer.loaded == 1)
@@ -584,7 +584,7 @@ const Events = Module("events", {
         while (now = Date.now(), now < end) {
             util.threadYield();
             //if ((now - start) % 1000 < 10)
-            //    dactyl.dump("waited: " + (now - start) + " ms");
+            //    util.dump("waited: " + (now - start) + " ms");
 
             if (!events.feedingKeys)
                 return false;
@@ -602,7 +602,7 @@ const Events = Module("events", {
         let ret = (buffer.loaded == 1);
         if (!ret)
             dactyl.echoerr("Page did not load completely in " + maxWaitTime + " seconds. Macro stopped.");
-        //dactyl.dump("done waiting: " + ret);
+        //util.dump("done waiting: " + ret);
 
         // sometimes the input widget had focus when replaying a macro
         // maybe this call should be moved somewhere else?
diff --git a/common/content/javascript.js b/common/content/javascript.js
index b32b366c..8c6c492f 100644
--- a/common/content/javascript.js
+++ b/common/content/javascript.js
@@ -62,6 +62,8 @@ const JavaScript = Module("javascript", {
             return [];
 
         let completions = [k for (k in this.iter(obj, toplevel))];
+        if (obj == modules) // Hack.
+            completions = completions.concat([k for (k in this.iter(jsmodules, toplevel))]);
         return completions;
     },
 
diff --git a/common/content/modules.js b/common/content/modules.js
index ad383e4f..bf0acd60 100644
--- a/common/content/modules.js
+++ b/common/content/modules.js
@@ -82,7 +82,6 @@ window.addEventListener("load", function onLoad() {
         });
     });
 
-    function dump(str) window.dump(String.replace(str, /\n?$/, "\n").replace(/^/m, services.get("dactyl:").name + ": "));
     const start = Date.now();
     const deferredInit = { load: [] };
     const seen = set();
@@ -136,7 +135,7 @@ window.addEventListener("load", function onLoad() {
                 fn();
         }
         catch (e) {
-            dump("Loading " + (module && module.className) + ": " + e + "\n" + (e.stack || ""));
+            util.dump("Loading " + (module && module.className) + ": " + e + "\n" + (e.stack || ""));
         }
         return modules[module.className];
     }
@@ -145,7 +144,7 @@ window.addEventListener("load", function onLoad() {
     deferredInit["load"].forEach(call);
     modules.times = update({}, defineModule.times);
 
-    dump("Loaded in " + (Date.now() - start) + "ms");
+    util.dump("Loaded in " + (Date.now() - start) + "ms");
 }, false);
 
 window.addEventListener("unload", function onUnload() {
diff --git a/common/content/quickmarks.js b/common/content/quickmarks.js
index 07cf7134..8a8646f2 100644
--- a/common/content/quickmarks.js
+++ b/common/content/quickmarks.js
@@ -157,7 +157,6 @@ const QuickMarks = Module("quickmarks", {
         commands.add(["qmarks"],
             "Show all QuickMarks",
             function (args) {
-                dactyl.dump(args);
                 args = args[0] || "";
 
                 // ignore invalid qmark characters unless there are no valid qmark chars
diff --git a/common/modules/base.jsm b/common/modules/base.jsm
index 859aeed8..33635641 100644
--- a/common/modules/base.jsm
+++ b/common/modules/base.jsm
@@ -137,7 +137,10 @@ function require(obj, name, from) {
     }
     catch (e) {
         dump("loading " + String.quote("resource://dactyl/" + name + ".jsm") + "\n");
-        dump("    " + e.fileName + ":" + e.lineNumber + ": " + e +"\n");
+        if (loaded.util)
+            util.reportError(e);
+        else
+            dump("    " + e.fileName + ":" + e.lineNumber + ": " + e +"\n");
     }
 }
 
@@ -151,7 +154,7 @@ defineModule("base", {
         "isObject", "isString", "isSubclass", "iter", "iterAll", "keys",
         "memoize", "properties", "requiresMainThread", "set", "update", "values"
     ],
-    use: ["services"]
+    use: ["services", "util"]
 });
 
 function Runnable(self, func, args) {
@@ -697,12 +700,7 @@ Class.Property.prototype.init = function () {};
 Class.extend = function extend(subclass, superclass, overrides) {
     subclass.superclass = superclass;
 
-    try {
-        subclass.prototype = Object.create(superclass.prototype);
-    }
-    catch(e) {
-        dump(e + "\n" + String.replace(e.stack, /^/gm, "    ") + "\n\n");
-    }
+    subclass.prototype = Object.create(superclass.prototype);
     update(subclass.prototype, overrides);
     subclass.prototype.constructor = subclass;
     subclass.prototype._class_ = subclass;
diff --git a/common/modules/sanitizer.jsm b/common/modules/sanitizer.jsm
index 55acbdee..0c57a174 100644
--- a/common/modules/sanitizer.jsm
+++ b/common/modules/sanitizer.jsm
@@ -153,7 +153,8 @@ const Sanitizer = Module("sanitizer", XPCOM([Ci.nsIObserver, Ci.nsISupportsWeakR
             catch (e) {
                 errors = errors || {};
                 errors[itemName] = e;
-                dump("Error sanitizing " + itemName + ": " + e + "\n" + e.stack + "\n");
+                util.dump("Error sanitizing " + itemName);
+                util.reportError(e);
             }
         }
 
@@ -172,7 +173,8 @@ const Sanitizer = Module("sanitizer", XPCOM([Ci.nsIObserver, Ci.nsISupportsWeakR
             catch (e) {
                 errors = errors || {};
                 errors[itemName] = e;
-                dump("Error sanitizing " + itemName + ": " + e + "\n" + e.stack + "\n");
+                util.dump("Error sanitizing " + itemName);
+                util.reportError(e);
             }
         return errors;
     }
diff --git a/common/modules/services.jsm b/common/modules/services.jsm
index 7460ab50..93daf28b 100644
--- a/common/modules/services.jsm
+++ b/common/modules/services.jsm
@@ -6,7 +6,8 @@
 
 Components.utils.import("resource://dactyl/base.jsm");
 defineModule("services", {
-    exports: ["Services", "services"]
+    exports: ["Services", "services"],
+    use: ["util"]
 });
 
 /**
@@ -72,7 +73,7 @@ const Services = Module("Services", {
         }
         catch (e) {
             // dactyl.log() is not defined at this time, so just dump any error
-            dump("Service creation failed for '" + classes + "': " + e + "\n");
+            util.dump("Service creation failed for '" + classes + "': " + e + "\n");
             return null;
         }
     },
diff --git a/common/modules/storage.jsm b/common/modules/storage.jsm
index 1888bb27..74b78c46 100644
--- a/common/modules/storage.jsm
+++ b/common/modules/storage.jsm
@@ -299,7 +299,7 @@ const File = Class("File", {
                     file.initWithPath(expandedPath);
             }
             catch (e) {
-                dump("dactyl: " + e + "\n" + String.replace(e.stack, /^/gm, "dactyl:  ") + "\n");
+                util.reportError(e);
                 return null;
             }
         }
diff --git a/common/modules/util.jsm b/common/modules/util.jsm
index dcb827b4..a2342e1a 100644
--- a/common/modules/util.jsm
+++ b/common/modules/util.jsm
@@ -57,7 +57,6 @@ const Util = Module("Util", {
                 if (observers[target])
                     observers[target].call(obj, subject, data);
             });
-        this.dactyl.dump(String(obj), obj instanceof Ci.nsIObserver);
         register("addObserver");
     },
 
@@ -230,9 +229,6 @@ const Util = Module("Util", {
      * Prints a message to the console. If <b>msg</b> is an object it is
      * pretty printed.
      *
-     * NOTE: the "browser.dom.window.dump.enabled" preference needs to be
-     * set.
-     *
      * @param {string|Object} msg The message to print.
      */
     dump: function dump_() {
@@ -676,6 +672,8 @@ const Util = Module("Util", {
         }
     },
 
+    maxErrors: 15,
+    errors: Class.memoize(function () []),
     reportError: function (error) {
         if (Cu.reportError)
             Cu.reportError(error);
@@ -686,16 +684,16 @@ const Util = Module("Util", {
                 stack: <>{String.replace(error.stack || Error().stack, /^/mg, "\t")}</>
             });
 
-            let errors = storage.newArray("errors", { store: false });
-            errors.toString = function () [String(v[0]) + "\n" + v[1] for ([k, v] in this)].join("\n\n");
-            errors.push([new Date, obj + obj.stack]);
+            this.errors.push([new Date, obj + "\n" + obj.stack]);
+            this.errors = this.errors.slice(-this.maxErrors);
+            this.errors.toString = function () [k + "\n" + v for ([k, v] in array.iterValues(this))].join("\n\n");
 
-            util.dump(String(error));
-            util.dump(obj);
-            util.dump("");
+            this.dump(String(error));
+            this.dump(obj);
+            this.dump("");
         }
         catch (e) {
-            dump(e);
+            this.dump(e);
         }
     },
 
diff --git a/pentadactyl/content/config.js b/pentadactyl/content/config.js
index a14c49e4..81a314d9 100644
--- a/pentadactyl/content/config.js
+++ b/pentadactyl/content/config.js
@@ -240,7 +240,6 @@ const Config = Module("config", ConfigBase, {
             });
     },
     completion: function () {
-        dactyl.dump("Load completion\n");
         var searchRunning = false; // only until Firefox fixes https://bugzilla.mozilla.org/show_bug.cgi?id=510589
         completion.location = function location(context) {
             if (!services.get("autoCompleteSearch"))