NegotiateAuth - Aims to create an plugin for the Mozilla-based browsers supporting the HTTP Negotiate authentication method. - http://negotiateauth.mozdev.org/
Mozcert - Enhances access to security certificates. - http://mozcert.mozdev.org/
Cookiemanager - A quest for better a cookie manager for Firefox. - http://cookiemanager.mozdev.org/
CookieCuller - A modified version of the Cookie Manager built into the Firefox/Mozilla browser. - http://cookieculler.mozdev.org/
cookiebar - An interface to your cookie manager, but it sits in your sidebar. It provides a quick way to look at your cookies, and to delete or block them. - http://cookiebar.mozdev.org/
BugMeNot - An extension that enables the user to bypass compulsory web site registration. - http://bugmenot.mozdev.org/