My good friend Daniel asked me yesterday how to change Firefox so that Shift+Enter auto-completes *.org instead of *.net. After about a 2 minute google session, I had the answer to share with everybody.

The ctrl-alt-backspace key combination was used to restart X-server and was recently disabled because of a upstream (X.org) design decision:

... this Firefox version, carries the code name "Namoroka" Alpha 1, and it is also currently referred to as Firefox.next. And like other Firefox Alphas, it does not bare the Firefox logo. This release uses the Gecko 1.9.2 engine and will likely include several interface improvements in later versions, such as new graphical tab-switching behavior, which was removed from 3.5 with Beta 2.

Among Firefox 3 pending improvements it a cool tab preview feature that shows actual thumbnails of the currently opened tabs. The feature is currently available as an experimental extension developed by Dão Gottwald, but could make its way to Firefox 3 final code.

"...The most obvious example is to compare the modern convention of multi-document tab-switching to the buffer-switching mechanisms you see in Emacs. Once you start opening a significant number of tabs, the number of documents you can open and see at the same time is limited by the width of your screen. For Firefox on this machine, the number is twelve[1] when it's running full-screen.

‘Gmrun’ is a run-program utility that provides bash-like TAB completion and history, the ability to run commands in a terminal using CTRL-Enter. CTRL-R/CTRL-S may be used for history searches, similar to ‘bash’.

One of the many changes in xserver 1.6 is switching the DontZap option's default so that the ctrl-alt-backspace option does not trigger X to terminate unless the user deliberately configures it to do so.

"...So far, the most useful new feature I’ve found in Firefox 3 is the much improved location bar autocomplete that unlike Firefox 2 which only looked for web addresses in my history, this one looks on visited and bookmarked page titles and tags along with web addresses..."

Since Ubuntu 9.04, the Ctrl-Alt-Backspace key combination to force a restart of X is now disabled by default, to eliminate the problem of accidentally triggering the key combination. In addition, the Ctrl-Alt-Backspace option is now configured as an X keymap (XKB) option, replacing the X server "DontZap" option and allowing per-user configuration of this setting.