Sep 3, 2010 15:45 GMT  ·  By

If you’re holding your breath while waiting for the 64-bit (x64) flavor of Firefox 4.0, feel free to exhale now. The next major iteration of Mozilla’s open source browser will support 32-bit (x86) platforms exclusively, despite some very promising work from the browser vendor early in the development process for version 4.0.

Mozilla’s Director of Firefox, Mike Beltzner confirmed the fact that an x64 flavor of Firefox won’t be added to the existing x86 version, per the 32-bit/64-bit Internet Explorer 8 model.

Firefox users should not despair though. Fact is that Mozilla hasn’t given up on delivering a 64-bit version of Firefox, just not with Firefox 4.0.

“I've been working on the list of supported platforms for Firefox 4 and wanted to provide an update on some decisions that have been reached,” Beltzner noted.

“In February of this year, there was a discussion in which we decided that the minimum supported version of Mac OS X would be 10.5 (Leopard).

“Early in the summer we decided to not yet provide supported 64-bit builds on Windows, and will instead work on delivering those in some future release.

“In July we decided that the minimum supported version of Windows would be Windows 2000.

“After some evaluation we decided this week to drop support for OSX/PPC; Firefox 4 Mac OS X binaries will ship as universal builds for i386/x86-64 only.

“We are considering dropping support for i386 architectures which do not support SSE2 (older Athlon CPUs, some VIA chipsets) but have not yet reached a final decision here,” he explained.

Back in May 2010, Mozilla revealed plans to start offering an x64 flavor of Firefox 4.0 for Windows.

Just days later, the browser vendor was providing the first nightly builds for download to early adopters. However, at this point in time it appears that plans of a 64-bit Firefox 4.0 won’t materialize.

Firefox 4.0 will continue to support the traditional platforms for which the browser has been available, namely Windows, Mac OS X and Linux.

Mozilla has set up a webpage with a list of the operating systems which will be supported by the successor of Firefox 3.6.

“•Microsoft Windows

◦32-bit builds only ◦minimum version: Windows 2000 ◦CPU architecture: i386, x86-64

•Mac OS X

◦32- and 64-bit builds (universal binary) ◦minimum version: Mac OS X 10.5 ◦CPU architecture: i386, x86-64

•Linux

◦32-bit builds only ◦minimum version: tbd ◦CPU architecture: i386, x86-64.”

Firefox 4.0 Beta 4 for Windows is available for download here.

Firefox 4.0 Beta 4 for Mac OS X is available for download
here.

Firefox 4.0 Beta 4 for Linux is available for download
here.