Firefox Client Customization Kit (Firefox CCK) allows people to create an extension that customizes the browser for a particular installation or deployment. Example customizations include adding an indentifier to the user agent string, changing the default home page, title bar text and the animated logo, preinstalling browser plugins and search engines, adding bookmarks, registry keys and certificates. The version 1.0 have just been released and allows the following customizations:

* Add identifer to the user agent string
* Change the default home page and startup override home page
* Change the title bar text
* Change the animated logo
* Change the web page and tooltip used for the animated logo
* Add a help menu item that links to a web page
* Provide sites for which popups and XPInstalls are allowed by default
* Preinstall browser plug-ins
* Preinstall search engines
* Add folders, bookmarks and live bookmarks to the personal toolbar
* Add folders, bookmarks and live bookmarks to the bookmarks folder
* Set default preferences
* Lock preferences
* Add registry keys (Windows only)
* Add certificates
* Set default proxy configurations
* Package other XPIs with your distribution
* Disable about:config

for more information : Firefox 1.5 CCK