Add-ons

MinimizeToTray revived by Nils Maier

Minimizes windows into the system tray.

Element Hiding Helper for Adblock Plus by Felix Dahlke

Fight the text ads! Element Hiding Helper is a companion extension for Adblock Plus meant to make creating element hiding rules easier.

Mozilla Archive Format, with MHT and Faithful Save by Christopher Ottley, Paolo Amadini

— Open web pages saved with Internet Explorer or other browsers (MHT)
— Save many tabs, video and audio reliably, in a single ZIP file (MAFF)
— Return to the original site you saved a page from, and more!

Key config by Martin Petricek

This add-on provides configurable keyboard shortcuts for several actions and a dialog to customize them.
All shortcuts can be redefined in Tools -> Key settings

Collector's Note Not to be confused with keyconfig, that one allows adding new keys.

Paste to Tab and Go by Zulkarnain K.

Paste URL or text to any tabs or a new tab and load it immediately, like 'Paste & Go' feature, but unlike 'Paste & Go', this extension will paste text from clipboard to a tab without focusing on the tab first.

Collector's Note Use this old Paste and Go extension instead for customizable shortcut key: http://pasteandgo2.mozdev.org/ or use Tab Utilities for similar shortcut function, but uncustomizable.