Mozilla Firefox 4.0!
I’ve been using the RCs for several weeks, and other than a few stability and tab issues I’ve been enjoying the improved performance and cleaner interface.
I’ve been swamped with work and studies as of late (I still haven’t uploaded my photos from the Weird Al concert!) but I hope to have a more detailed review up in the coming days, particularly some of the new extension sandboxing, DNT headers and other goodies. Stay tuned :).