Mozilla to launch 64-bit Firefox 41 to stable channel

Firefox users who prefer a 64-bit version of the web browser instead of a 32-bit version on Windows will be able to install and use a 64-bit stable channel version when Firefox 41 gets released.
 
Firefox 41, which will be released on September 22, 2015 if things go as planned, will be offered as a 32-bit and 64-bit version for the Windows platform.
 
Full Article