Firebug FAQ http://www.getfirebug.com/faq.html
Why doesn't Firebug work on Linux? Firebug does work on Linux, but some distributions don't compile Mozilla correctly, and it is missing the components that Firebug depends on. Even more common is the case of individual Linux users compiling their own Firefox binaries incorrectly. If you compile your own Firefox, please read this topic on the Firebug Discussion group for information how to make a Firebug-compatible build.
USE="mozdevelop" が必要
I would have paid to know this 3 weeks ago, but now that I know, I thought I'd share with everyone.... go to about:buildconfig in firefox... if you see: --disable-jsd you definitely have problems, lol... rebuild firefox with: --enable-jsd --enable-extensions=default,typeaheadfind,venkman if you are on gentoo, all you need to do is add the "mozdevelop" use flag. kenny The amount of excitement and joy I feel -- especially since firebug is coming out with a new version --- is really nerdy :)
http://groups.google.com/group/firebug/browse_thread/thread/7c1a9c0886d98070/6791b68e3a829ceb