SeaMonkey

Allows organizion of notes into a tree.

Makes a startup page out of your bookmarks. The layout of this page is fully customizable.

Adds a dropdown to the location bar with additional features.

An add-on to Mozilla that lets you add a tagline, random or specifically chosen by you, to the end of an email or newsgroup posting, or to the clipboard for pasting into a Web-based email or message board.

A simple, accessible GUI that allows the modification of any preference set within the browser environment.

A quick hack to add Google and Dictionary lookups to the context menu in Mozilla.

Adds a new hotkey (Ctrl+;) which focuses on the first text field on the page.

Manages multiples tabs on browser and mail.