Nuacht

Unlikely to restart x64 development in 2013 Mozilla this week suspended development of a 64-bit version of Firefox for Windows, citing add-on incompatibilities and low priority for the project.
Mozilla officially launched its new Firefox 43 browser, and the biggest highlight is 64-bit support for the Windows version. This will allow for larger apps, faster execution, and enhanced security.
In addition to the unveiling of a 64-bit version of Firefox, Mozilla has also enhanced its Private Browsing and Tracking Protection feature.