This HTML demonstrates a Firefox 3 performance bug in the gnome version of Firefox 3 (my current version is Build identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9) Gecko/2008061015 Firefox/3.0).
Scrolling becomes very slow and freezes the browser and the xserver. The firefox process takes a whole cpu core. (Try scrolling up and down real fast)
I noticed the bug in the Facebook application Armies, and extracted the important code.
3000+ lines of HTML & 10,000+ lines of CSS were shrunk down to about 60 lines of CSS+HTML.
As a web developer i am a great supporter of Firefox and would love to see the Linux version as performant as the Windows and MacOS Version (both tested with this site).
Further information on this bug (or a similar) can be found on Launchpad, Bugzilla,mozilla.org or in my Blog (Screen Caputring).
I am using Ubuntu Hardy btw…
Of course this is w3c validated: