These days the Mozilla Foundation is feeling the heat.  Microsoft Corp. (MSFT) has delivered a surprisingly sporty and compatible Internet Explorer 9.  And Google Inc.'s (GOOG) Chrome browser is becoming the first new browser in some time to gobble up a significant market share.

I. Firefox 5 Blazes Ahead on Schedule

But nothing lays concerns to rest better than adopting an aggressive schedule and sticking to it.  That's exactly what Mozilla did, with the release of Firefox 5's second beta.

Delivered right on schedule, the new build features speed improvements and a number of new features, including:

• Added support for CSS animations
• Added support for switching Firefox development channels
• 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

The inclusion of CSS animations support was particularly important, as the Webkit source (which Chrome and Apple, Inc.'s (AAPL) Safari browser are based on) already supports it.  Mozilla and its collaborators also made some tweaks to the GUI art, which they say are subtle, but will be noticed if you return to FF4.

Aside from new functionality and speed-ups, the beta also resolves many stability issues and other bugs that cropped up in Firefox 4.  A full log of these changes is found here.  Full release notes can be found here.  And last, but not least, the download can be found here.

Firefox 5 is scheduled to release June 21 -- less than a month from now.  It will contend with Internet Explorer 10, which is currently being previewed, and Chrome 12, which is currently being beta tested.

II. Opera Mini 6 Hits the iPad, iPhone

Yesterday also saw the release of Opera Mini 6 for the iPad and iPhone.  The first major release for the iOS platform since its launch title -- Opera Mini 5 -- Norwegian software company Opera Software ASA (OPERA) is hoping to replicate its previous success.  Opera saw 1 million downloads of Mini 5 for the iPhone/iPad in a mere 24 hours after its release.

Available on the iTunes store now for free, the new browser features:

• Much faster and smoother panning and zooming
• Share buttons which are compatible with My Opera, Facebook, Twitter or vKontakte
• A new" jazzed-up" skin
• Redesigned Opera menus

It also reportedly gives the browser a healthy injection of speed.

Opera’s, CEO Lars Boilesen compared the release to a rock concert, stating, "I would compare it to walking onto the stage and hearing the roar of the crowd. We have put in a lot of rehearsal and clever thought behind the new experience. The Opera Mini browser has always kicked up the tempo when downloading pages; now the browsing flows along to a smooth, easy beat."

While Opera is seeing a bit more competition these days -- namely from the Firefox Mobile browser for Android -- it's still makes the most used mobile browsing pair in the world, Opera Mini and Opera Mobile.  These mobile browsers are unique in that they leverage heavy server-side compression, something the competition still hasn't embraced. The net effect for users is that in areas with poor signal or low data speeds pages load much faster in Opera Mini/Mobile than in their competitors.