Please visit http://mozilla.zeniko.ch/fission.html for further information.
Theme compatibility: Some themes might break with Fission installed. If yours does, please contact the theme's author about the incompatibility. For issues with the default theme, post a screenshot to the thread at http://forums.mozillazine.org/viewtopic.php?t=594322 . Thanks.
Firefox 4.0 support: I won't support Firefox 4.0 or later. If you're a developer and want to add Firefox 4.0 support yourself, please contact me in the forum thread linked above. Otherwise please try the Status-4-Evar extension from https://addons.mozilla.org/addon/status-4-evar/ instead.