Great! It's fun to see the browser wars in full swing again. Competition makes better browsers for everyone.
Firefox 6 has WebSockets support as well - a very interesting one for possibly developing multiplayer games...
Websockets, WebM, data- class of attributes. This could be used to get parameters and infos from the webpage.
Also Firefox 6 for developpers.
Updated my FF, installed Firebug 1.8.1 and I was ready to rock.
Also Ash: they seem to have done something with the audio support.
udio API
Firefox is changing the way media is integrated on the Web. HTML5 makes it easy for developers to use JavaScript to read and write audio data. We?ve exposed the raw audio data so you can create great sounds!
I must admit I didn't quite get that part.
2nd EDIT: Interesting page.
SVG, APIs, CSS formating, CSS unit scaling, WebGL.
*drools*