This morning I decided to give Firefox 3.5 Beta 4 from Mozilla Labs a try.
I'm really interested in a lot of what they're doing, including their development of HTML 5 support for
<video> elements and closer CSS 2.1 support including text shadows. I haven't tested the former, but the latter is definitely working; not sure whether I'd ever use such shadows on my own pages but it's good to see Firefox catching up to Safari/WebKit, Opera and Konqueror/KHTML in this regard.
Mac users like me will be pleased to note some quite significant cosmetic changes which make Firefox look more Mac-like. Context menus now finally match Mac OS X Leopard's rounded corners, the bookmark bar has a much more subdued gradient which looks classier and the toolbar itself takes up less screen real estate.
Given I use so many extensions I admit I was worried how many of them would break in the beta; to my relief only two were, and neither are security related. SSL Blacklist (now my favourite extension alongside NoScript) in the version I had was incompatible, but updating to version 4.0.31 and the SSL Blacklist Local Database 1.0.7 fixed this. Clipmarks reports to be compatible, but alas doesn't work for me at all.
Compatible with 3.5b4 Not compatible with 3.5b4 Adblock Plus 1.0.2
British English Dictionary 1.19
Permit Cookies 0.6.2
SSL Blacklist 4.0.31
SSL Blacklist Local D'Base 1.0.7
Tree Style Tab 0.7.2009051501
I look forward to the final release, as usual the Mozilla folks are doing a fantastic job.