Jun 16, 2011 12:41 GMT  ·  By

The Release Candidate development milestone of the next major iteration of Firefox is now available to early adopters for testing.

I would say that Firefox 5 RC signals the proximity of the final release of Firefox 4.0’s successor, if it weren’t for the fact that Mozilla already confirmed that it will launch the next version of its open source browser on June 21st, 2011.

“As part of Mozilla’s new rapid release development process the beta development channel has been updated with a Firefox release candidate,” revealed Christian Legnitto, Firefox release manager at Mozilla.

Just yesterday I was telling Softpedia users that Mozilla was offering a new Beta Build of Firefox 5. At the same time, the people building the open source browser were discussing the possibility of making Firefox 5.0b6 the RC development milestone.

It turned out that the company needed to implement just one additional fix, and this led to the creation of yet another Beta update, Firefox 5.0b7.

Later yesterday, Mozilla slapped the RC label on top of Firefox 5.0b7, and released it to testers.

“For desktop users, if you previously installed a beta version of Firefox 4 you will receive an automated update notification within 24 to 48 hours,” Legnitto added. “We highly encourage add-on developers to test their add-ons with the new version and mark them as compatible as soon as possible.”

Because of the overhaul of Firefox’s development process and release cycle, Firefox 5 RC is still served to early adopters through the Beta channel.

What Mozilla is actually saying with this release is that it’s gearing up to finalize the browser and offer it to end users, which should happen next week, on June 21st.

Here are the changes highlighted by Mozilla for Firefox 5 RC:

“• Added support for CSS animations

• The Do-Not-Track header preference has been moved to increase discoverability

• Improved canvas, JavaScript, memory, and networking performance

• Improved standards support for HTML5, XHR, MathML, SMIL, and canvas

• Improved spell checking for some locales

• Improved desktop environment integration for Linux users

• WebGL content can no longer load cross-domain textures

• Background tabs have setTimeout and setInterval clamped to 1000ms to improve performance

• The Firefox development channel switcher introduced in previous Firefox Beta updates has been removed.”

Firefox 5 Release Candidate (RC) (Firefox 5.0b7) for Windows is available for download here.

Firefox 5 Release Candidate (RC) (Firefox 5.0b7) for Mac is available for download here.

Firefox 5 Release Candidate (RC) (Firefox 5.0b7) for Linux is available for download here.

Firefox 6 Aurora for Windows is available for download here.

Firefox 6 Aurora for Mac is available for download here.

Firefox 6 Aurora for Linux is available for download here.