ChatZilla is normally used as part of SeaMonkey, or an extension to other browsers. However, it can also run under XULRunner, allowing ChatZilla to be used standalone, independent of a web browser.
Extract the XULRunner archive to a sensible location.
For example, C:\Program Files\ or /opt/.
Save the ChatZilla .zip file inside the XULRunner directory. Open a terminal window.
Note: Ensure you run the XULRunner commands as an administrator. For example, on Windows 7, right-click Command Prompt on the Start Menu and choose "Run as administrator"., or on Linux, use "sudo" before the XULRunner commands.
Switch to the XULRunner directory.
For example, enter cd C:\Program Files\XULRunner or cd /opt/xulrunner.
Install ChatZilla by entering xulrunner --install-app chatzilla-0.9.88-xr.zip.
Note: You can delete the ChatZilla .zip file after this step.
If you need to copy over settings or scripts, use the ChatZilla command /pref profilePath to find your profile.
XULRunner checks regularly for new ChatZilla versions. Updates are not downloaded without your permission.
You can get more information on the update process, or subscribe to my news page to hear about new versions.
Since 0.9.71, the Extension manager can be opened from the ChatZilla menu.
I have one extension (Windows only): MinimizeToTray for ChatZilla.
The experimental platform-specific packages below include XULRunner 12. The "App only" package requires at least XULRunner 2.
You don't need to build Mozilla to build ChatZilla. You just need Mercurial, Python, and something to apply a diff.