Nice build, a lot of bugfixes, only works on Nokia N800 and N810, and Windows Mobile builds are on the way, but there are builds of Fennec for Windows, Mac and Linux. Check it out here.
But since M8, we have a very nice feature: Tracemonkey.
about:config in the awesome(fennec) bar. Filter by:
jit and activate (to
true) the two preferences.
Maybe Tracemonkey for Firefox is: «Hey! Gmail looks like it is a little bit more smooth», but for Fennec (where processors are slow), «Hey, it tooks only one second!! not 5!!»
So, Fennec Team: THANKS!!