Mozilla Working on Windows 8 “Modern Interface” Edition of Firefox
Dubbed "Firefox Metro," work has already begun on it and Firefox 26 for Windows, which it will be packaged alongside of. The touch-optimized browser is scheduled to reach Mozilla's Aurora channel on September 16 and Beta channel on October 28, which means users will have a first real glimpse of the updated build as early as next month.

This has been a long time coming. Mozilla first mentioned a Metro version of its popular browser way back in February 2012, revealing a prototype two months later. A very early preview version would debut in October 2012 a few weeks ahead of Microsoft's Windows 8 launch. Initially, Mozilla hoped to have the browser ready by January 2013.