With Firefox 14 out of the sandbox and into the world, Mozilla is now focusing its efforts on polishing up the next upgrade, Firefox 15. The next Firefox version is due out in six weeks, but the beta version is already available for download from the beta release channel.

Mozilla focused on improving memory management, and the latest Firefox 15 beta version should patch up most memory leaks from Firefox add-ons that devour system memory. Mozilla's MemShrink project, designed to address those memory management issues, brings the Firefox 15 beta closer to the stable version of the browser. The latest beta focused on long browser sessions and the impact add-ons have on Firefox.

Firefox 15 beta is likely to be "drastically" faster than Firefox 14 in some cases, Mozilla developer Nicholas Nethercote wrote in a blog post. As previously mentioned, the changes in the latest beta focus on memory leaks, which Nethercote said occur when a program allocates some of the computer's memory to use, but fails to release it when the task is completed. Back in January, Nethercote noted that memory leaks in add-ons play a major role in the browser's instability. Mozilla has fixed many of those add-ons since then, but Nethercote said Firefox should be able to handle add-ons that still gouge the system's memory.

"We have confirmed, via in-house testing and from real-world telemetry data, that [Firefox 15 progress from the MemShrink research] prevents the vast majority of leaks that occur in existing add-ons," added the developer.

According to the blog post announcing the new Firefox 15 beta, the latest version also introduces built-in PDF support to consumers, support for version 3 of Google's SPDY networking protocol, as well as native support for the Opus audio codec, an open source format providing better compression than AAC, MP3, or Ogg.

Meanwhile, developers also get some changes in the new Firefox 15 beta, including a JavaScript debugger, WebGL improvements, an event timer, and JavaScript JIT (just-in-time) engine improvements for faster browsing.

Firefox for Android 15 beta also comes with a set of changes. The Firefox for Android installer will automatically detect if you are using a phone or a tablet, and will install the proper interface without requiring any additional input. The Android beta includes the ability to swipe to close tabs, switch to a site's desktop view from the Menu, and search in-page. Users can also pause, resume, cancel, or retry a download from the Download Manager, import bookmarks and history from the default Android browser, as well as toggle which data to clear from Settings. The new Opus and SPDY v3 are also supported on the Firefox for Android beta version.