New features in Firefox 3.5

Like its brethren browsers Google Chrome and Internet Explorer 8, Firefox is moving toward separating tabs into system processes, increasing browsing stability and taking advantage of increasingly common multi-processor systems.

The wiki outline of the "Content Processes" project states that the browser UI itself, and every page opened in a tab, would be split into a separate running process, which would "Provide better application UI responsiveness" and improve stability. In terms of how most Lifehacker-ish types use Firefox—with a good number of useful extensions—this could only be seen as good news, as extension-related slow-downs might be walled off from actual content.

When would this happen? The wiki outline suggests a seriously rough "bootstrap," with a non-Firefox browser operating the browser "chrome" (interface) and a single tab as separate processes, is scheduled by July 15 of this year. Phase II, "Parallel Improvements," would see further work on safely connecting the browser chrome to the content, and is roughly estimated for Nov. 1, 2009. Extensions, performance optimization, and multi-process content aren't even on a rough roadmap yet, so don't expect a multi-process Firefox in 2009.

Mozilla Links suggests Firefox could perhaps speed up its multi-process adoption by borrowing frameworks from the open-source well from which Google Chrome draws, Chromium. But what do you think? Is a multi-process, potentially more stable and CPU-adapted (and Chrome-like) browser the next big thing you've wanted from Firefox, or are there other areas you'd like to see worked on? Contribute to the open-source discussion in the comments.

Windows only: Reader David writes in about a user-contributed build of Firefox 3.5 Beta 4 that uses some custom patches and optimized build settings for faster, less memory-intensive browsing.

Multiple downloads are provided, each one optimized for the processor you are using—most modern PCs can use the P3 build, provided in both regular and portable downloads. The Flash and Windows Media plugins are already pre-installed, and the build uses the new profile-guided optimization option to speed it up even further. In our brief testing, it definitely feels fast and doesn't appear to use much memory—but since this is a user-contributed, unofficial build by an unknown (to us, anyway) author, you may want to proceed with caution.

Firefox 3.5 Beta 4 Optimized Build is a free download, Windows only. If you do try it out, let us know in the comments if you see any speed or memory usage benefits. Thanks, David!