Mozilla quietly ceases Firefox 64-bit development

Mozilla engineering manager Benjamin Smedberg has asked developers to stop nightly builds for Firefox versions optimized to run on 64-bit versions of Windows.

A developer thread posted on the Google Groups mozilla.dev.planning discussion board, titled "Turning off win64 builds" by Smedberg proposed the move.

Claiming that 64-bit Firefox is a "constant source of misunderstanding and frustration," the engineer wrote that the builds often crash, many plugins are not available in 64-bit versions, and hangs are more common due to a lack of coding which causes plugins to function incorrectly. In addition, Smedberg argues that this causes users to feel "second class," and crash reports between 32-bit and 64-bit versions are difficult to distinguish between for the stability team.

Users can still run 32-bit Firefox on 64-bit Windows.

Although originally willing to shelve the idea for a time if it proved controversial, Smedberg later, well, shelved that idea:

Thank you to everyone who participated in this thread. Given the existing information, I have decided to proceed with disabling windows 64-bit nightly and hourly builds. Please let us consider this discussion closed unless there is critical new information which needs to be presented.

The engineer then posted a thread titled "Disable windows 64 builds" on Bugzilla, asking developers to "stop building windows [sic] 64 builds and tests." These include the order to stop building Windows 64-bit nightly builds and repatriate existing Windows 64-bit nightly users onto Windows 32-bit builds using a custom update.

In order to stave off argument, even though one participant suggested that 50 percent of nightly testers were using the system, perhaps as an official 64-bit version of Firefox for Windows has never been released, Smedberg said it was "not the place to argue about this decision, which has already been made."