A year and a half after the last major Firefox release, Firefox 3 Release Candidate 1 is here with a very long list of new features and improvements.

Performance

Firefox 3 gets several performance improvement gains. Among them, profile guided optimizations (PGO) provides an optimized Firefox build based on the way it internally works. So far it is only available for Windows. Linux should follow shortly and Mac OS X could also make it before final release.

A very noticeable gain can be seen in JavaScript.

Memory wise, a much needed memory cycle collector is now in place to take care of freeing memory no longer used by modules that requested it but failed to release it properly.

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Representatives of Mozilla were in Seattle today to talk about the Firefox 3.0 browser in advance of its release next month. I sat down this morning to talk about Firefox and the browser market in general with Mozilla's Mike Beltzner, whose title is "phenomenologist," and Vlad Vukicevic, a Mozilla "infrastructuralist.

One of the subjects we discussed was the Smart Location Bar -- a Firefox 3.0 feature known informally as the Awesome Bar. The feature gives the browser's address bar a mechanism for letting users quickly return to Web pages, without bookmarking them, even if they don't remember the address. As people type, the tool searches for that text in the addresses and titles of pages that they've visited previously. It also can search tags -- keywords that users associate with a particular page.

Read More 'Awesome Bar': Firefox's next killer feature?