This chart shows memory leak management test results comparing how Firefox 14 and Firefox 15 handle memory after 150 tabs have been closed. Yes, 150. (Credit: Mozilla)

As with many tech code-names, MemShrink doesn't sound particularly exciting. And yet, the memory leak-managing project at Mozilla finally sees some of its biggest changes reach the vast majority of people using Firefox with today's major update.

Mozilla expects that the new Firefox 15 for PCs (download for Windows | Mac | Linux) finally will put an end to the multitude of memory-managing issues that have plagued Firefox for years. As we noted in July when Firefox 15 went beta, the MemShrink project has spent much of its time fixing how the browser handles add-ons that contribute to memory problems. A "memory leak" is when a program destabilizes itself after grabbing memory to use for a task, but then unsuccessfully or improperly releases that memory after the task is done. Firefox engineers claimed that the browser had rid itself of many of these problems, but add-ons and lengthy browser sessions still contributed leaks.

This update, they say, addresses those leaks. In my ongoing use of Firefox alpha and beta builds, there are notably fewer crashes with Firefox 15. Whether the changes are enough to coax back people who've abandoned Firefox over the past few years is another matter entirely.

Firefox 15 has built-in PDF support, but it's still not turned on by default. However, there is now native support for the Opus audio codec, an open-source format that offers better compression than MP3, Ogg, or AAC; and SPDY version 3 compliance, an update to Google's networking protocol.

Web developers and especially game developers get some changes in Firefox 15, too, including a JavaScript debugger, an event timer, WebGL improvements, and JavaScript just-in-time (JIT) engine improvements for faster browsing. Also in Firefox 15 is support for compressed textures for better video memory use. Mozilla has prepared a demo to show what compressed textures can do.

Tablets are getting a new Firefox for Android look. (Credit: Mozilla)

The revamped and faster interface that arrived in Firefox 15 for Android (download) works on tablets as of this update. This includes a new start page, which Mozilla calls the Awesome Screen; the new layout; dramatically faster page-load times; and Flash support on Honeycomb, which was a big factor in delaying the launch of the tablet version.

Firefox for Android autodetects your device and installs the proper interface without any additional input required.

The Android version of Firefox on all devices now has a Menu option for jumping to a site's desktop view; closing tabs with a swipe; and searching within a page. The Download Manager lets you pause, resume, cancel, and retry a failed download; you can toggle which data to clear from Settings; and you can import your bookmarks and history from the default Android browser. Under-the-hood improvements include the new Opus, and SPDY v3.

The short rundown on Firefox 15 for Android is that it now very closely approximates many of the core features in Firefox for desktops.

Firefox 15 release notes can be read here, and Firefox 15 for Android release notes are here.

Correction: This story originally stated that PDF support was turned on in Firefox 15 by default, but that is not the case.