Mozilla has released Firefox 4.0 Beta 1, officially. I, however, have been using the nightly builds of what will become Firefox 4.0 for about a month. That said, if you want to give 4.0b1 a spin, you might want to consider changing a few of the UI settings. As always, while the nightly versions might be so buggy as to interfere with the space-time continuum, beta grade software, while stable enough, still might be somewhat annoyingly buggy, so avoid if your browsing is mission critical, i.e. not relating to Muslim outreach.
Strangely, while 64-bit Fx for Win64 is available in the nightlies, there is no Fx64/Win64 “official” 4.0b1, only 32-bit Fx (which will run just fine on Windows 64, as long as the OS and CPU are x86_64, and not that obsolete Itanium stuff). But go figure — Fx-64 for Mac64 and Linux64 are there. I hope this means that Mozilla isn’t backtracking on its commitment to Fx-64 on Win64, though it really wouldn’t matter if they did backtrack — Win64 users won’t rush to a 64-bit browser of any variety until Flash releases a 64-bit plugin for Windows. (Java already has, but nobody really cares about Java anymore, except for those who say they can run Java.) Fx-64 on Mac 64 might or might not have this, (I think it might because Mac is UNIX), but Fx-64 on Linux 64 has had the ability to run 32-bit plugins in a “wrapper” mode for awhile, even though Flash 64 and Java 64 for Linux 64 have existed for just as long.
