Mozilla has been promising a version of Firefox designed for the new Windows 8 UI for a year now, and has trickled out a few details and previews since then. It's made a considerably bigger step this week though by releasing the browser into its Nightly channel, which lets anyone who's willing to venture beyond stable releases take it for a spin. As Mozilla's Asa Dotzler puts it, "there's plenty of work still to do, but it's stable enough that we're ready for more and more regular testing." It seems folks are indeed having some problems with it in its current state, but you can try it out for yourself at the source link.