diff --git a/common/content/buffer.js b/common/content/buffer.js
index 19d69cc4..cd7221b9 100644
--- a/common/content/buffer.js
+++ b/common/content/buffer.js
@@ -135,6 +135,19 @@ function Buffer() //{{{
         pageInfo[option] = [fn, title];
     }
 
+    function openUploadPrompt(elem)
+    {
+        commandline.input("Upload file: ", function (path) {
+                let file = io.getFile(path);
+
+                if (!file.exists())
+                    return liberator.beep();
+
+                elem.value = file.path;
+        },
+        { completer: completion.file, default: elem.value });
+    }
+
     /////////////////////////////////////////////////////////////////////////////}}}
     ////////////////////// OPTIONS /////////////////////////////////////////////////
     /////////////////////////////////////////////////////////////////////////////{{{
@@ -360,16 +373,13 @@ function Buffer() //{{{
         function (count)
         {
             if (count < 1 && buffer.lastInputField)
-            {
-                buffer.lastInputField.focus();
-            }
+                buffer.focusElement(buffer.lastInputField);
             else
             {
                 let elements = [];
                 let matches = buffer.evaluateXPath(
-                    // TODO: type="file"
-                    "//input[not(@type) or @type='text' or @type='password'] | //textarea[not(@disabled) and not(@readonly)] |" +
-                    "//xhtml:input[not(@type) or @type='text' or @type='password'] | //xhtml:textarea[not(@disabled) and not(@readonly)]"
+                    "//input[not(@type) or @type='text' or @type='password' or @type='file'] | //textarea[not(@disabled) and not(@readonly)] |" +
+                    "//xhtml:input[not(@type) or @type='text' or @type='password' or @type='file'] | //xhtml:textarea[not(@disabled) and not(@readonly)]"
                 );
 
                 for (let match in matches)
@@ -382,12 +392,10 @@ function Buffer() //{{{
                 if (elements.length > 0)
                 {
                     count = Math.min(Math.max(count, 1), elements.length);
-                    elements[count - 1].focus();
+                    buffer.focusElement(elements[count - 1]);
                 }
                 else
-                {
                     liberator.beep();
-                }
             }
         },
         { flags: Mappings.flags.COUNT });
@@ -509,6 +517,14 @@ function Buffer() //{{{
     ////////////////////// COMMANDS ////////////////////////////////////////////////
     /////////////////////////////////////////////////////////////////////////////{{{
 
+    commands.add(["frameo[nly]"],
+        "Show only the current frame's page",
+        function (args)
+        {
+            liberator.open(tabs.localStore.focusedFrame.document.documentURI);
+        },
+        { argCount: "0" });
+
     commands.add(["ha[rdcopy]"],
         "Print current document",
         function (args)
@@ -1063,18 +1079,10 @@ function Buffer() //{{{
                 elem.contentWindow.focus();
                 return;
             }
-            else if (elemTagName == "input" && elem.getAttribute('type').toLowerCase() == "file")
+            else if (elemTagName == "input" && elem.type.toLowerCase() == "file")
             {
-                commandline.input("Upload file: ", function (path)
-                    {
-                        let file = io.getFile(path);
-
-                        if (!file.exists())
-                            return liberator.beep();
-
-                        elem.value = file.path;
-                    }
-                    , {completer: completion.file, default: elem.value});
+                openUploadPrompt(elem);
+                buffer.lastInputField = elem;
                 return;
             }
 
@@ -1182,18 +1190,9 @@ function Buffer() //{{{
                 offsetX = Number(coords[0]) + 1;
                 offsetY = Number(coords[1]) + 1;
             }
-            else if (localName == "input" && elem.getAttribute('type').toLowerCase() == "file")
+            else if (localName == "input" && elem.type.toLowerCase() == "file")
             {
-                commandline.input("Upload file: ", function (path)
-                    {
-                        let file = io.getFile(path);
-
-                        if (!file.exists())
-                            return liberator.beep();
-
-                        elem.value = file.path;
-                    }
-                    , {completer: completion.file, default: elem.value});
+                openUploadPrompt(elem);
                 return;
             }
 
@@ -1931,7 +1930,7 @@ function Marks() //{{{
             }
 
             if (!ok)
-                liberator.echoerr("E20: Mark not set"); // FIXME: move up?
+                liberator.echoerr("E20: Mark not set");
         },
 
         /**
diff --git a/common/content/commands.js b/common/content/commands.js
index b6a2bdd7..420b78f8 100644
--- a/common/content/commands.js
+++ b/common/content/commands.js
@@ -34,13 +34,25 @@ the terms of any one of the MPL, the GPL or the LGPL.
  * A class representing Ex commands. Instances are created by
  * the {@link Commands} class.
  *
+ * @param {string[]} specs The names by which this command can be invoked.
+ *     These are specified in the form "com[mand]" where "com" is a unique
+ *     command name prefix.
+ * @param {string} description A short one line description of the command.
+ * @param {function} action The action invoked by this command when executed.
+ * @param {Object} extraInfo An optional extra configuration hash. The
+ *     following properties are supported.
+ *         argCount  - See (@link Command#argCount)
+ *         bang      - See (@link Command#bang)
+ *         completer - See (@link Command#completer)
+ *         count     - See (@link Command#count)
+ *         heredoc   - See (@link Command#heredoc)
+ *         literal   - See (@link Command#literal)
+ *         options   - See (@link Command#options)
+ *         serial    - See (@link Command#serial)
  * @private
  */
 function Command(specs, description, action, extraInfo) //{{{
 {
-    if (!specs || !action)
-        return null;
-
     if (!extraInfo)
         extraInfo = {};
 
@@ -91,7 +103,7 @@ function Command(specs, description, action, extraInfo) //{{{
     /** @property {string[]} All of this command's long and short names. */
     this.names       = expandedSpecs.names; // return all command name aliases
 
-    /** @property {string} This command's description, as shown in :exinfo */
+    /** @property {string} This command's description, as shown in :exusage */
     this.description = description || "";
     /** @property {function (Args)} The function called to execute this command. */
     this.action      = action;
diff --git a/common/content/completion.js b/common/content/completion.js
index c37e9cd5..cf0a142f 100644
--- a/common/content/completion.js
+++ b/common/content/completion.js
@@ -46,7 +46,6 @@ the terms of any one of the MPL, the GPL or the LGPL.
  * @author Kris Maglione <maglione.k@gmail.com>
  * @constructor
  */
-
 function CompletionContext(editor, name, offset) //{{{
 {
     if (!(this instanceof arguments.callee))
diff --git a/common/content/editor.js b/common/content/editor.js
index f2952281..4245b5ad 100644
--- a/common/content/editor.js
+++ b/common/content/editor.js
@@ -690,7 +690,7 @@ function Editor() //{{{
         // motion = b, 0, gg, G, etc.
         executeCommandWithMotion: function (cmd, motion, count)
         {
-            if (!typeof count == "number" || count < 1)
+            if (typeof count != "number" || count < 1)
                 count = 1;
 
             if (cmd == motion)
@@ -705,12 +705,12 @@ function Editor() //{{{
             {
                 case "j":
                     this.executeCommand("cmd_beginLine", 1);
-                    this.executeCommand("cmd_selectLineNext", count+1);
+                    this.executeCommand("cmd_selectLineNext", count + 1);
                     break;
                 case "k":
                     this.executeCommand("cmd_beginLine", 1);
                     this.executeCommand("cmd_lineNext", 1);
-                    this.executeCommand("cmd_selectLinePrevious", count+1);
+                    this.executeCommand("cmd_selectLinePrevious", count + 1);
                     break;
                 case "h":
                     this.executeCommand("cmd_selectCharPrevious", count);
diff --git a/common/content/events.js b/common/content/events.js
index 3e643cdc..18acc004 100644
--- a/common/content/events.js
+++ b/common/content/events.js
@@ -1733,38 +1733,6 @@ function Events() //{{{
             // Stub for something else, presumably. Not in any documented
             // interface.
             onLinkIconAvailable: function () {}
-        },
-
-        // TODO: move to options.js?
-        prefObserver: {
-            register: function ()
-            {
-                // better way to monitor all changes?
-                this._branch = services.get("pref").getBranch("").QueryInterface(Ci.nsIPrefBranch2);
-                this._branch.addObserver("", this, false);
-            },
-
-            unregister: function ()
-            {
-                if (this._branch)
-                    this._branch.removeObserver("", this);
-            },
-
-            observe: function (aSubject, aTopic, aData)
-            {
-                if (aTopic != "nsPref:changed")
-                    return;
-
-                // aSubject is the nsIPrefBranch we're observing (after appropriate QI)
-                // aData is the name of the pref that's been changed (relative to aSubject)
-                switch (aData)
-                {
-                    case "accessibility.browsewithcaret":
-                        let value = options.getPref("accessibility.browsewithcaret", false);
-                        liberator.mode = value ? modes.CARET : modes.NORMAL;
-                        break;
-                }
-             }
         }
     }; //}}}
 
@@ -1782,10 +1750,8 @@ function Events() //{{{
     }
     catch (e) {}
 
-    self.prefObserver.register();
     liberator.registerObserver("shutdown", function () {
             self.destroy();
-            self.prefObserver.unregister();
     });
 
     window.addEventListener("keypress", wrapListener("onKeyPress"),    true);
diff --git a/common/content/finder.js b/common/content/finder.js
index 765dc170..9c8e5560 100644
--- a/common/content/finder.js
+++ b/common/content/finder.js
@@ -30,7 +30,6 @@ the terms of any one of the MPL, the GPL or the LGPL.
 
 // TODO: proper backwards search - implement our own component?
 //     : implement our own highlighter?
-//     : frameset pages
 //     : <ESC> should cancel search highlighting in 'incsearch' mode and jump
 //       back to the presearch page location - can probably use the same
 //       solution as marks
@@ -48,8 +47,6 @@ function Finder() //{{{
     ////////////////////// PRIVATE SECTION /////////////////////////////////////////
     /////////////////////////////////////////////////////////////////////////////{{{
 
-    // FIXME:
-    //var self = this;               // needed for callbacks since "this" is the "liberator" object in a callback
     var found = false;               // true if the last search was successful
     var backwards = false;           // currently searching backwards
     var searchString = "";           // current search string (without modifiers)
diff --git a/common/content/hints.js b/common/content/hints.js
index 846bb8cf..0d93a315 100644
--- a/common/content/hints.js
+++ b/common/content/hints.js
@@ -638,8 +638,8 @@ function Hints() //{{{
          * @param {boolean} allowWordOverleaping  Whether to allow non-contiguous
          *         words to match.
          *
-         * @return {function(String):bool} A function that will filter only
-         *         hints that match as above.
+         * @return {function(String):boolean} A function that will filter only
+         *     hints that match as above.
          */
         function wordStartsWithMatcher(hintString, allowWordOverleaping) //{{{
         {
@@ -886,7 +886,7 @@ function Hints() //{{{
                         context.completions = [[k, v.prompt] for ([k, v] in Iterator(hintModes))];
                     },
                     onChange: function () { modes.pop() },
-                    onCancel: function (arg) { arg && setTimeout(function () hints.show(arg), 0); },
+                    onCancel: function (arg) { arg && setTimeout(function () hints.show(arg), 0); }
                 });
         }, { flags: Mappings.flags.COUNT });
 
@@ -897,14 +897,16 @@ function Hints() //{{{
     return {
 
         /**
-         * Create a new hint mode
+         * Creates a new hint mode.
          *
          * @param {String} mode  The letter that identifies this mode.
-         * @param {String} description  The description to display to the user about this mode.
-         * @param {function(Node)} callback  The function to be called with the element that matches.
-         * @param {function():String} selector  The function that returns an XPath selector to decide
-         *                                      which elements can be hinted (the default returns
-         *                                      options.hinttags)
+         * @param {String} description  The description to display to the user
+         *     about this mode.
+         * @param {function(Node)} callback  The function to be called with the
+         *     element that matches.
+         * @param {function():String} selector  The function that returns an
+         *     XPath selector to decide which elements can be hinted (the
+         *     default returns options.hinttags).
          */
         addMode: function (mode)
         {
@@ -912,11 +914,11 @@ function Hints() //{{{
         },
 
         /**
-         * Update the display of hints.
+         * Updates the display of hints.
          *
          * @param {String} minor  Which hint mode to use.
          * @param {String} filter  The filter to use.
-         * @param {Object} win  The window in which we are showing hints
+         * @param {Object} win  The window in which we are showing hints.
          */
         show: function (minor, filter, win)
         {
@@ -968,7 +970,7 @@ function Hints() //{{{
         },
 
         /**
-         * Handle an event
+         * Handle an event.
          *
          * @param {Event} event  The event to handle.
          */
diff --git a/common/content/io.js b/common/content/io.js
index a3f3a248..cd05d0e9 100644
--- a/common/content/io.js
+++ b/common/content/io.js
@@ -335,7 +335,7 @@ function IO() //{{{
         function ()
         {
             let list = template.tabular(["<SNR>", "Filename"], ["text-align: right; padding-right: 1em;"],
-                ([i + 1, file] for ([i, file] in Iterator(scriptNames))));  // TODO: add colon?
+                ([i + 1, file] for ([i, file] in Iterator(scriptNames))));  // TODO: add colon and remove column titles for pedantic Vim compatibility?
 
             commandline.echo(list, commandline.HL_NORMAL, commandline.FORCE_MULTILINE);
         },
@@ -345,11 +345,13 @@ function IO() //{{{
         "Read Ex commands from a file",
         function (args)
         {
-            // FIXME: "E172: Only one file name allowed"
-            io.source(args[0], args.bang);
+            if (args.length > 1)
+                liberator.echoerr("E172: Only one file name allowed");
+            else
+                io.source(args[0], args.bang);
         },
         {
-            argCount: "1",
+            argCount: "+", // FIXME: should be "1" but kludged for proper error message
             bang: true,
             completer: function (context) completion.file(context, true)
         });
@@ -878,7 +880,6 @@ lookup:
             let dirs = getPathsFromPathList(options["runtimepath"]);
             let found = false;
 
-            // FIXME: should use original arg string
             liberator.echomsg("Searching for \"" + paths.join(" ") + "\" in \"" + options["runtimepath"] + "\"", 2);
 
             outer:
@@ -902,7 +903,7 @@ lookup:
             }
 
             if (!found)
-                liberator.echomsg("not found in 'runtimepath': \"" + paths.join(" ") + "\"", 1); // FIXME: should use original arg string
+                liberator.echomsg("not found in 'runtimepath': \"" + paths.join(" ") + "\"", 1);
 
             return found;
         },
@@ -1001,7 +1002,7 @@ lookup:
                             {
                                 let lineNumber = i + 1;
 
-                                // FIXME: messages need to be able to specify
+                                // TODO: messages need to be able to specify
                                 // whether they can be cleared/overwritten or
                                 // should be appended to and the MOW opened
                                 liberator.echoerr("Error detected while processing " + file.path, commandline.FORCE_MULTILINE);
diff --git a/common/content/liberator.js b/common/content/liberator.js
index 8894cf3a..0b1cf852 100644
--- a/common/content/liberator.js
+++ b/common/content/liberator.js
@@ -1069,7 +1069,7 @@ const liberator = (function () //{{{
          * Opens one or more URLs. Returns true when load was initiated, or
          * false on error.
          *
-         * @param {FIXME} urls Either a URL string or an array of URLs.
+         * @param {string|string[]} urls Either a URL string or an array of URLs.
          *     The array can look like this:
          *       ["url1", "url2", "url3", ...]
          *     or:
diff --git a/common/content/mappings.js b/common/content/mappings.js
index d8502044..d110a4c2 100644
--- a/common/content/mappings.js
+++ b/common/content/mappings.js
@@ -30,33 +30,68 @@ the terms of any one of the MPL, the GPL or the LGPL.
 
 // Do NOT create instances of this class yourself, use the helper method
 // mappings.add() instead
-function Map(modes, cmds, description, action, extraInfo) //{{{
+/**
+ * A class representing key mappings. Instances are created by the
+ * {@link Mappings} class.
+ *
+ * @param {number[]} modes The modes in which this mapping is active.
+ * @param {string[]} keys The key sequences which are bound to
+ *     <b>action</b>.
+ * @param {string} description A short one line description of the key mapping.
+ * @param {function} action The action invoked by each key sequence.
+ * @param {Object} extraInfo An optional extra configuration hash. The
+ *     following properties are supported.
+ *         flags   - See (@link Map#flags)
+ *         noremap - See (@link Map#noremap)
+ *         rhs     - See (@link Map#rhs)
+ *         silent  - See (@link Map#silent)
+ * @private
+ */
+function Map(modes, keys, description, action, extraInfo) //{{{
 {
-    if (!modes || (!cmds || !cmds.length) || !action)
-        return null;
-
     if (!extraInfo)
         extraInfo = {};
 
+    /** @property {number[]} All of the modes for which this mapping applies. */
     this.modes = modes;
-    // only store keysyms with uppercase modifier strings
-    this.names = cmds.map(function (cmd) cmd.replace(/[casm]-/g, String.toUpperCase));
+    /** @property {string[]} All of this mapping's names (key sequences). */
+    this.names = keys.map(function (cmd) cmd.replace(/[casm]-/g, String.toUpperCase)); // only store keysyms with uppercase modifier strings
+    /** @property {function (number)} The function called to execute this mapping. */
     this.action = action;
 
+    /** @property {number} See (@link Mappings#flags) */
     this.flags = extraInfo.flags || 0;
+    /** @property {string} This mapping's description, as shown in :viusage. */
     this.description = description || "";
+    /** @property {string} The literal RHS expansion of this mapping. */
     this.rhs = extraInfo.rhs || null;
+    /** @property {boolean} Whether the RHS of the mapping should expand mappings recursively. */
     this.noremap = extraInfo.noremap || false;
+    /** @property {boolean} Whether any output from the mapping should be echoed on the command line. */
     this.silent = extraInfo.silent || false;
 };
 
 Map.prototype = {
 
-    hasName: function (name)
-    {
-        return this.names.indexOf(name) >= 0;
-    },
+    /**
+     * Returns whether this mapping can be invoked by a key sequence matching
+     * <b>name</b>.
+     *
+     * @param {string} name The name to query.
+     * @returns {boolean}
+     */
+    hasName: function (name) this.names.indexOf(name) >= 0,
 
+    /**
+     * Execute the action for this mapping.
+     *
+     * @param {string} motion The motion argument if accepted by this mapping.
+     *     E.g. "w" for "dw"
+     * @param {number} count The associated count. E.g. "5" for "5j"
+     * @default -1
+     * @param {string} argument The normal argument if accepted by this
+     *     mapping. E.g. "a" for "ma"
+     */
     execute: function (motion, count, argument)
     {
         let args = [];
@@ -100,9 +135,9 @@ function Mappings() //{{{
     {
         let where = userMap ? user : main;
         map.modes.forEach(function (mode) {
-                if (!(mode in where))
-                    where[mode] = [];
-                where[mode].push(map);
+            if (!(mode in where))
+                where[mode] = [];
+            where[mode].push(map);
         });
     }
 
@@ -255,6 +290,7 @@ function Mappings() //{{{
     /////////////////////////////////////////////////////////////////////////////{{{
 
     addMapCommands("",  [modes.NORMAL, modes.VISUAL], "");
+
     for (let mode in modes.mainModes)
         if (mode.char)
             addMapCommands(mode.char,
@@ -296,13 +332,40 @@ function Mappings() //{{{
         __iterator__: function () mappingsIterator([modes.NORMAL], main),
 
         // used by :mkvimperatorrc to save mappings
+        /**
+         * Returns a user-defined mappings iterator for the specified
+         * <b>mode</b>.
+         *
+         * @param {number} mode The mode to return mappings from.
+         * @returns {Iterator(Map)}
+         */
         getUserIterator: function (mode) mappingsIterator(mode, user),
 
+        /**
+         * Add a new default key mapping.
+         *
+         * @param {number[]} modes The modes that this mapping applies to.
+         * @param {string[]} keys The key sequences which are bound to
+         *     <b>action</b>.
+         * @param {string} description A description of the key mapping.
+         * @param {function} action The action invoked by each key sequence.
+         * @param {Object} extra An optional extra configuration hash.
+         */
         add: function (modes, keys, description, action, extra)
         {
             addMap(new Map(modes, keys, description, action, extra), false);
         },
 
+        /**
+         * Add a new user-defined key mapping.
+         *
+         * @param {number[]} modes The modes that this mapping applies to.
+         * @param {string[]} keys The key sequences which are bound to
+         *     <b>action</b>.
+         * @param {string} description A description of the key mapping.
+         * @param {function} action The action invoked by each key sequence.
+         * @param {Object} extra An optional extra configuration hash.
+         */
         addUserMap: function (modes, keys, description, action, extra)
         {
             keys = keys.map(expandLeader);
@@ -318,20 +381,41 @@ function Mappings() //{{{
             addMap(map, true);
         },
 
+        /**
+         * Returns the map from <b>mode</b> named <b>cmd</b>.
+         *
+         * @param {number} mode The mode to search.
+         * @param {string} cmd The map name to match.
+         * @returns {Map}
+         */
         get: function (mode, cmd)
         {
             mode = mode || modes.NORMAL;
             return getMap(mode, cmd, user) || getMap(mode, cmd, main);
         },
 
+        /**
+         * Returns the default map from <b>mode</b> named <b>cmd</b>.
+         *
+         * @param {number} mode The mode to search.
+         * @param {string} cmd The map name to match.
+         * @returns {Map}
+         */
         getDefault: function (mode, cmd)
         {
             mode = mode || modes.NORMAL;
             return getMap(mode, cmd, main);
         },
 
-        // returns an array of mappings with names which START with "cmd" (but are NOT "cmd")
-        getCandidates: function (mode, cmd)
+        /**
+         * Returns an array of maps with names starting with but not equal to
+         * <b>prefix</b>.
+         *
+         * @param {number} mode The mode to search.
+         * @param {string} prefix The map prefix string to match.
+         * @returns {Map[]}
+         */
+        getCandidates: function (mode, prefix)
         {
             let mappings = user[mode].concat(main[mode]);
             let matches = [];
@@ -340,10 +424,10 @@ function Mappings() //{{{
             {
                 for (let [,name] in Iterator(map.names))
                 {
-                    if (name.indexOf(cmd) == 0 && name.length > cmd.length)
+                    if (name.indexOf(prefix) == 0 && name.length > prefix.length)
                     {
                         // for < only return a candidate if it doesn't look like a <c-x> mapping
-                        if (cmd != "<" || !/^<.+>/.test(name))
+                        if (prefix != "<" || !/^<.+>/.test(name))
                             matches.push(map);
                     }
                 }
@@ -352,28 +436,57 @@ function Mappings() //{{{
             return matches;
         },
 
+        /*
+         * Returns the map leader string used to replace the special token
+         * "<Leader>" when user mappings are defined.
+         *
+         * @returns {string}
+         */
+        // FIXME: property
         getMapLeader: function ()
         {
             let leaderRef = liberator.variableReference("mapleader");
             return leaderRef[0] ? leaderRef[0][leaderRef[1]] : "\\";
         },
 
-        // returns whether the user added a custom user map
-        hasMap: function (mode, cmd)
-        {
-            return user[mode].some(function (map) map.hasName(cmd));
-        },
+        /**
+         * Returns whether there is a user-defined mapping <b>cmd</b> for the
+         * specified <b>mode</b>.
+         *
+         * @param {number} mode The mode to search.
+         * @param {string} cmd The candidate key mapping.
+         * @returns {boolean}
+         */
+        hasMap: function (mode, cmd) user[mode].some(function (map) map.hasName(cmd)),
 
+        /**
+         * Remove the user-defined mapping named <b>cmd</b> for <b>mode</b>.
+         *
+         * @param {number} mode The mode to search.
+         * @param {string} cmd The map name to match.
+         */
         remove: function (mode, cmd)
         {
             removeMap(mode, cmd);
         },
 
+        /**
+         * Remove all user-defined mappings for <b>mode</b>.
+         *
+         * @param {number} mode The mode to remove all mappings from.
+         */
         removeAll: function (mode)
         {
             user[mode] = [];
         },
 
+        /**
+         * Lists all user-defined mappings matching <b>filter</b> for the
+         * specified <b>modes</b>.
+         *
+         * @param {number[]} modes An array of modes to search.
+         * @param {string} filter The filter string to match.
+         */
         list: function (modes, filter)
         {
             let modeSign = "";
@@ -413,7 +526,6 @@ function Mappings() //{{{
             }
             commandline.echo(list, commandline.HL_NORMAL, commandline.FORCE_MULTILINE);
         }
-
     };
     //}}}
 }; //}}}
diff --git a/common/content/options.js b/common/content/options.js
index 4973a957..da19b982 100644
--- a/common/content/options.js
+++ b/common/content/options.js
@@ -32,9 +32,6 @@ the terms of any one of the MPL, the GPL or the LGPL.
 // options.add() instead
 function Option(names, description, type, defaultValue, extraInfo) //{{{
 {
-    if (!names || !type)
-        return null;
-
     if (!extraInfo)
         extraInfo = {};
 
@@ -808,7 +805,7 @@ function Options() //{{{
                                      .map(function (pref) [pref, ""])]);
     });
 
-    return {
+    const self = {
 
         OPTION_SCOPE_GLOBAL: 1,
         OPTION_SCOPE_LOCAL:  2,
@@ -820,6 +817,37 @@ function Options() //{{{
             return (v for ([k, v] in Iterator(sorted)));
         },
 
+        prefObserver: {
+            register: function ()
+            {
+                // better way to monitor all changes?
+                this._branch = services.get("pref").getBranch("").QueryInterface(Ci.nsIPrefBranch2);
+                this._branch.addObserver("", this, false);
+            },
+
+            unregister: function ()
+            {
+                if (this._branch)
+                    this._branch.removeObserver("", this);
+            },
+
+            observe: function (subject, topic, data)
+            {
+                if (topic != "nsPref:changed")
+                    return;
+
+                // subject is the nsIPrefBranch we're observing (after appropriate QI)
+                // data is the name of the pref that's been changed (relative to subject)
+                switch (data)
+                {
+                    case "accessibility.browsewithcaret":
+                        let value = options.getPref("accessibility.browsewithcaret", false);
+                        liberator.mode = value ? modes.CARET : modes.NORMAL;
+                        break;
+                }
+             }
+        },
+
         add: function (names, description, type, defaultValue, extraInfo)
         {
             if (!extraInfo)
@@ -1067,8 +1095,15 @@ function Options() //{{{
                 this.popContext();
             }
         }
-    };
-    //}}}
+    }; //}}}
+
+    self.prefObserver.register();
+    liberator.registerObserver("shutdown", function () {
+            self.prefObserver.unregister();
+    });
+
+    return self;
+
 }; //}}}
 
 // vim: set fdm=marker sw=4 ts=4 et:
diff --git a/common/content/tabs.js b/common/content/tabs.js
index c3d9f059..6eb98d67 100644
--- a/common/content/tabs.js
+++ b/common/content/tabs.js
@@ -30,6 +30,9 @@ the terms of any one of the MPL, the GPL or the LGPL.
 
 // TODO: many methods do not work with Thunderbird correctly yet
 
+/**
+ * @instance tabs
+ */
 function Tabs() //{{{
 {
     ////////////////////////////////////////////////////////////////////////////////
@@ -307,7 +310,6 @@ function Tabs() //{{{
 
             if (arg)
             {
-                arg = arg.toLowerCase();
                 let removed = 0;
                 let matches = arg.match(/^(\d+):?/);
 
@@ -318,15 +320,27 @@ function Tabs() //{{{
                 }
                 else
                 {
+                    let str = arg.toLowerCase();
                     let browsers = getBrowser().browsers;
+
                     for (let i = browsers.length - 1; i >= 0; i--)
                     {
-                        let title = browsers[i].contentTitle.toLowerCase() || "";
-                        let uri = browsers[i].currentURI.spec.toLowerCase();
-                        let host = browsers[i].currentURI.host.toLowerCase();
+                        let host, title, uri = browsers[i].currentURI.spec;
+                        if (browsers[i].currentURI.schemeIs("about"))
+                        {
+                            host = "";
+                            title = "(Untitled)";
+                        }
+                        else
+                        {
+                            host = browsers[i].currentURI.host;
+                            title = browsers[i].contentTitle;
+                        }
 
-                        if (host.indexOf(arg) >= 0 || uri == arg ||
-                            (special && (title.indexOf(arg) >= 0 || uri.indexOf(arg) >= 0)))
+                        [host, title, uri] = [host, title, uri].map(String.toLowerCase);
+
+                        if (host.indexOf(str) >= 0 || uri == str ||
+                            (special && (title.indexOf(str) >= 0 || uri.indexOf(str) >= 0)))
                         {
                             tabs.remove(tabs.getTab(i));
                             removed++;
@@ -398,7 +412,7 @@ function Tabs() //{{{
             if (arg)
             {
                 if (/^\d+$/.test(arg))
-                    tabs.select("-" + arg, true); // FIXME: urgh!
+                    tabs.select("-" + arg, true);
                 else
                     liberator.echoerr("E488: Trailing characters");
             }
@@ -676,8 +690,16 @@ function Tabs() //{{{
 
     return {
 
+        /**
+         * @property {Object} The previously accessed tab or null if no tab
+         *     other than the current one has been accessed.
+         */
         get alternate() alternates[1],
 
+        /**
+         * @property {Iterator(Object)} A genenerator that returns all browsers
+         *     in the current window.
+         */
         get browsers()
         {
             let browsers = getBrowser().browsers;
@@ -685,10 +707,13 @@ function Tabs() //{{{
                 yield [i, browsers[i]];
         },
 
-        get tabsBound() {
-            return Boolean(styles.get(true, "tab-binding"))
-        },
-        set tabsBound(val) {
+        /**
+         * @property {boolean} Whether the tab numbering XBL binding has been
+         *     applied.
+         */
+        get tabsBound() Boolean(styles.get(true, "tab-binding")),
+        set tabsBound(val)
+        {
             let fragment = liberator.has("MacUnix") ? "tab-mac" : "tab";
             if (!val)
                 styles.removeSheet(true, "tab-binding");
@@ -699,8 +724,14 @@ function Tabs() //{{{
                     ".tabbrowser-tab[busy] > .tab-icon > .tab-icon-image { list-style-image: url('chrome://global/skin/icons/loading_16.png') !important; }");
         },
 
+        /**
+         * @property {number} The number of tabs in the current window.
+         */
         get count() getBrowser().mTabs.length,
 
+        /**
+         * @property {Object} The local options store for the current tab.
+         */
         get options()
         {
             let store = this.localStore;
@@ -709,6 +740,15 @@ function Tabs() //{{{
             return store.options;
         },
 
+        /**
+         * Returns the local state store for the tab at the specified
+         * <b>tabIndex</b>. If <b>tabIndex</b> is not specified then the
+         * current tab is used.
+         *
+         * @param {number} tabIndex
+         * @returns {Object}
+         */
+        // FIXME: why not a tab arg? Why this and the property?
         getLocalStore: function (tabIndex)
         {
             let tab = this.getTab(tabIndex);
@@ -717,8 +757,15 @@ function Tabs() //{{{
             return tab.liberatorStore;
         },
 
+        /**
+         * @property {Object} The local state store for the currently selected
+         *     tab.
+         */
         get localStore() this.getLocalStore(),
 
+        /**
+         * @property {Object} The tab browser strip.
+         */
         get tabStrip()
         {
             let tabStrip = null;
@@ -732,18 +779,40 @@ function Tabs() //{{{
             return tabStrip;
         },
 
-        // @returns the index of the currently selected tab starting with 0
+        /**
+         * @property {Object[]} The array of closed tabs for the current
+         *     session.
+         */
+        get closedTabs()
+        {
+            return services.get("json").decode(services.get("sessionStore").getClosedTabData(window));
+        },
+
+        /**
+         * Returns the index of <b>tab</b> or the index of the currently
+         * selected tab if <b>tab</b> is not specified. This is a 0-based
+         * index.
+         *
+         * @param {Object} tab A tab from the current tab list.
+         * @returns {number}
+         */
         index: function (tab)
         {
             if (tab)
                 return Array.indexOf(getBrowser().mTabs, tab);
-
-            return getBrowser().mTabContainer.selectedIndex;
+            else
+                return getBrowser().mTabContainer.selectedIndex;
         },
 
         // TODO: implement filter
-        // @returns an array of tabs which match filter
-        get: function (filter)
+        /**
+         * Returns an array of all tabs in the tab list.
+         *
+         * @returns {Object[]}
+         */
+        // FIXME: why not return the tab element?
+        //      : unused? Remove me.
+        get: function ()
         {
             let buffers = [];
             for (let [i, browser] in this.browsers)
@@ -756,6 +825,13 @@ function Tabs() //{{{
             return buffers;
         },
 
+        /**
+         * Returns the index of the tab containing <b>content</b>.
+         *
+         * @param {Object} content Either a content window or a content
+         *     document.
+         */
+        // FIXME: Only called once...necessary?
         getContentIndex: function (content)
         {
             for (let [i, browser] in this.browsers)
@@ -766,6 +842,14 @@ function Tabs() //{{{
             return -1;
         },
 
+        /**
+         * Returns the tab at the specified <b>index</b> or the currently
+         * selected tab if <b>index</b> is not specified. This is a 0-based
+         * index.
+         *
+         * @param {number} index The index of the tab required.
+         * @returns {Object}
+         */
         getTab: function (index)
         {
             if (index != undefined)
@@ -774,26 +858,44 @@ function Tabs() //{{{
                 return getBrowser().mCurrentTab;
         },
 
-        get closedTabs()
-        {
-            return services.get("json").decode(services.get("sessionStore").getClosedTabData(window));
-        },
-
+        /**
+         * Lists all tabs matching <b>filter</b>.
+         *
+         * @param {string} filter A filter matching a substring of the tab's
+         *     document title or URL.
+         */
         list: function (filter)
         {
             completion.listCompleter("buffer", filter);
         },
 
-        // wrap causes the movement to wrap around the start and end of the tab list
-        // NOTE: position is a 0 based index
+        /**
+         * Moves a tab to a new position in the tab list.
+         *
+         * @param {Object} tab The tab to move.
+         * @param {string} spec See {@link indexFromSpec}.
+         * @param {boolean} wrap Whether an out of bounds <b>spec</b> causes
+         *     the destination position to wrap around the start/end of the tab
+         *     list.
+         */
         move: function (tab, spec, wrap)
         {
             let index = indexFromSpec(spec, wrap);
             getBrowser().moveTabTo(tab, index);
         },
 
-        // quitOnLastTab = 1: quit without saving session
-        // quitOnLastTab = 2: quit and save session
+        /**
+         * Removes the specified <b>tab</b> from the tab list.
+         *
+         * @param {Object} tab
+         * @param {number} count
+         * @param {boolean} focusLeftTab Focus the tab to the left of the removed tab.
+         * @param {number} quitOnLastTab Whether to quit if the tab being
+         *     deleted is the only tab in the tab list:
+         *         1 - quit without saving session
+         *         2 - quit and save session
+         */
+        // FIXME: what is quitOnLastTab {1,2} all about then, eh? --djk
         remove: function (tab, count, focusLeftTab, quitOnLastTab)
         {
             let removeOrBlankTab = {
@@ -874,25 +976,38 @@ function Tabs() //{{{
             }
         },
 
+        /**
+         * Removes all tabs from the tab list except the specified <b>tab</b>.
+         *
+         * @param {Object} tab The tab to keep.
+         */
         keepOnly: function (tab)
         {
             getBrowser().removeAllTabsBut(tab);
         },
 
+        /**
+         * Selects the tab at the position specified by <b>spec</b>.
+         *
+         * @param {string} spec See {@link indexFromSpec}
+         * @param {boolean} wrap Whether an out of bounds <b>spec</b> causes
+         *     the selection position to wrap around the start/end of the tab
+         *     list.
+         */
         select: function (spec, wrap)
         {
             let index = indexFromSpec(spec, wrap);
             // FIXME:
             if (index == -1)
             {
-                liberator.beep(); // XXX: move to ex-handling?
+                liberator.beep();
                 return;
             }
             getBrowser().mTabContainer.selectedIndex = index;
         },
 
         /**
-         * Reload the specified tab.
+         * Reloads the specified tab.
          *
          * @param {Object} tab The tab to reload.
          * @param {boolean} bypassCache Whether to bypass the cache when
@@ -912,7 +1027,7 @@ function Tabs() //{{{
         },
 
         /**
-         * Reload all tabs.
+         * Reloads all tabs.
          *
          * @param {boolean} bypassCache Whether to bypass the cache when
          *     reloading.
@@ -941,7 +1056,7 @@ function Tabs() //{{{
         },
 
         /**
-         * Stop loading the specified tab.
+         * Stops loading the specified tab.
          *
          * @param {Object} tab The tab to stop loading.
          */
@@ -954,7 +1069,7 @@ function Tabs() //{{{
         },
 
         /**
-         * Stop loading all tabs.
+         * Stops loading all tabs.
          */
         stopAll: function ()
         {
@@ -962,8 +1077,20 @@ function Tabs() //{{{
                 browser.stop();
         },
 
-        // "buffer" is a string which matches the URL or title of a buffer, if it
-        // is null, the last used string is used again
+        /**
+         * Selects the tab containing the specified <b>buffer</b>.
+         *
+         * @param {string} buffer A string which matches the URL or title of a
+         *     buffer, if it is null, the last used string is used again.
+         * @param {boolean} allowNonUnique Whether to select the first of
+         *     multiple matches.
+         * @param {number} count If there are multiple matches select the
+         *     count'th match.
+         * @param {boolean} reverse Whether to search the buffer list in
+         *     reverse order.
+         *
+         */
+        // FIXME: help!
         switchTo: function (buffer, allowNonUnique, count, reverse)
         {
             if (buffer == "")
@@ -1037,6 +1164,12 @@ function Tabs() //{{{
             }
         },
 
+        /**
+         * Clones the specified <b>tab</b> and append it to the tab list.
+         *
+         * @param {Object} tab The tab to clone.
+         * @param {boolean} activate Whether to select the newly cloned tab.
+         */
         cloneTab: function (tab, activate)
         {
             let newTab = getBrowser().addTab();
@@ -1048,6 +1181,12 @@ function Tabs() //{{{
             return newTab;
         },
 
+        /**
+         * Detaches the specified <b>tab</b> and open it in a new window. If no
+         * tab is specified the currently selected tab is detached.
+         *
+         * @param {Object} tab The tab to detach.
+         */
         detachTab: function (tab)
         {
             if (!tab)
@@ -1060,6 +1199,9 @@ function Tabs() //{{{
             this.remove(tab, 1, false, 1);
         },
 
+        /**
+         * Selects the alternate tab.
+         */
         selectAlternateTab: function ()
         {
             if (tabs.alternate == null || tabs.getTab() == tabs.alternate)
@@ -1085,6 +1227,10 @@ function Tabs() //{{{
         // tab that was selected when the session was created.  As a result the
         // alternate after a restart is often incorrectly tab 1 when there
         // shouldn't be one yet.
+        /**
+         * Called on each TabSelect event to update the tab selection history.
+         * See (@link tabs.alternate).
+         */
         updateSelectionHistory: function ()
         {
             alternates = [this.getTab(), alternates[0]];
diff --git a/common/content/template.js b/common/content/template.js
index 85614d66..ee149ab2 100644
--- a/common/content/template.js
+++ b/common/content/template.js
@@ -44,12 +44,12 @@ const template = {
         return <>{xml}</>;
     },
 
-    completionRow: function completionRow(item, class)
+    completionRow: function completionRow(item, highlightGroup)
     {
         if (typeof icon == "function")
             icon = icon();
 
-        if (class)
+        if (highlightGroup)
         {
             var text = item[0] || "";
             var desc = item[1] || "";
@@ -61,7 +61,7 @@ const template = {
         }
 
         // <e4x>
-        return <div highlight={class || "CompItem"} style="white-space: nowrap">
+        return <div highlight={highlightGroup || "CompItem"} style="white-space: nowrap">
                    <!-- The non-breaking spaces prevent empty elements
                       - from pushing the baseline down and enlarging
                       - the row.
diff --git a/muttator/content/config.js b/muttator/content/config.js
index b83cf099..a9c7980a 100644
--- a/muttator/content/config.js
+++ b/muttator/content/config.js
@@ -187,9 +187,9 @@ const config = { //{{{
 
             var stateListener =
             {
-                QueryInterface: function (aIID)
+                QueryInterface: function (id)
                 {
-                    if (aIID.equals(Components.interfaces.nsIDocumentStateListener))
+                    if (id.equals(Components.interfaces.nsIDocumentStateListener))
                         return this;
                     throw Components.results.NS_NOINTERFACE;
                 },
diff --git a/vimperator/NEWS b/vimperator/NEWS
index d9ebe362..a30cf99e 100644
--- a/vimperator/NEWS
+++ b/vimperator/NEWS
@@ -4,6 +4,7 @@
     * TabMixPlus (and other tab extensions) should work much better now
       together with Vimperator unless you :set guioptions+=[nN]
     * remove 'preload' option. You can fake it by some custom javascript in your init file
+    * add :frameonly
     * add :stopall
     * add :tabdo
     * add 'encoding'
diff --git a/vimperator/TODO b/vimperator/TODO
index 93a3ced1..ab3b5970 100644
--- a/vimperator/TODO
+++ b/vimperator/TODO
@@ -5,6 +5,7 @@ ARCHITECTURE:
 - modular help system
 
 BUGS:
+- :mkvimperatorrc now adds spurious vmap and nmap entries
 - add window resize support to hints
 - searching backwards incrementally does not work i.e. with 'incsearch' set
 - http://msdn2.microsoft.com/en-us/library/ms535258.aspx does not scroll with j/k/etc.
diff --git a/vimperator/content/bookmarks.js b/vimperator/content/bookmarks.js
index cec44ff3..fc3b578b 100644
--- a/vimperator/content/bookmarks.js
+++ b/vimperator/content/bookmarks.js
@@ -601,19 +601,19 @@ function Bookmarks() //{{{
         getSearchURL: function getSearchURL(text, useDefsearch)
         {
             let url = null;
-            let aPostDataRef = {};
+            let postData = {};
             let searchString = (useDefsearch ? options["defsearch"] + " " : "") + text;
 
             // we need to make sure our custom alias have been set, even if the user
             // did not :open <tab> once before
             this.getSearchEngines();
 
-            url = window.getShortcutOrURI(searchString, aPostDataRef);
+            url = window.getShortcutOrURI(searchString, postData);
             if (url == searchString)
                 url = null;
 
-            if (aPostDataRef && aPostDataRef.value)
-                return [url, aPostDataRef.value];
+            if (postData && postData.value)
+                return [url, postData.value];
             else
                 return url; // can be null
         },
diff --git a/vimperator/locale/en-US/buffer.txt b/vimperator/locale/en-US/buffer.txt
index 680a360f..4a6975e0 100644
--- a/vimperator/locale/en-US/buffer.txt
+++ b/vimperator/locale/en-US/buffer.txt
@@ -327,6 +327,14 @@ Normally this command operates on the text zoom; if used with [!], it
 operates on full zoom.
 ________________________________________________________________________________
 
+section:Working{nbsp}with{nbsp}frames[frames]
+
+|:frameo| |:frameonly|
+||:frameo[nly]|| +
+________________________________________________________________________________
+Show only the current frame's page.
+________________________________________________________________________________
+
 section:Copying{nbsp}text[copying,yanking]
 
 When running in X11, the text of the following commands is not only
diff --git a/vimperator/locale/en-US/index.txt b/vimperator/locale/en-US/index.txt
index cd9aa2d4..3da260a3 100644
--- a/vimperator/locale/en-US/index.txt
+++ b/vimperator/locale/en-US/index.txt
@@ -183,6 +183,7 @@ section:Ex{nbsp}commands[ex-cmd-index,:index]
 ||[c]:execute[c]|| Execute the argument as an Ex command +
 ||[c]:exusage[c]|| List all Ex commands with a short description +
 ||[c]:finish[c]|| Stop sourcing a script file +
+||[c]:frameonly[c]|| Show only the current frame's page +
 ||[c]:forward[c]|| Go forward in the browser history +
 ||[c]:hardcopy[c]|| Print current document +
 ||[c]:help[c]|| Display help +
diff --git a/xulmus/content/bookmarks.js b/xulmus/content/bookmarks.js
index 184457e6..4daf5530 100644
--- a/xulmus/content/bookmarks.js
+++ b/xulmus/content/bookmarks.js
@@ -601,13 +601,14 @@ function Bookmarks() //{{{
         getSearchURL: function getSearchURL(text, useDefsearch)
         {
             let url = null;
-            let aPostDataRef = {};
+            let postData = {};
             let searchString = (useDefsearch ? options["defsearch"] + " " : "") + text;
 
             // we need to make sure our custom alias have been set, even if the user
             // did not :open <tab> once before
             this.getSearchEngines();
 
+            // ripped from Firefox
             function getShortcutOrURI(aURL, aPostDataRef)
             {
                 var shortcutURL = null;
@@ -676,13 +677,13 @@ function Bookmarks() //{{{
                     return shortcutURL;
             }
 
-            url = getShortcutOrURI(searchString, aPostDataRef);
+            url = getShortcutOrURI(searchString, postData);
 
             if (url == searchString)
                 url = null;
 
-            if (aPostDataRef && aPostDataRef.value)
-                return [url, aPostDataRef.value];
+            if (postData && postData.value)
+                return [url, postData.value];
             else
                 return url; // can be null
         },