Apr 29, 2011 06:28 GMT  ·  By

The first update for Firefox 4.0 is now available for download. Customers that already deployed the latest iteration of Mozilla’s open source browser can now install Firefox 4.0.1. Firefox 4.0 enjoyed a great deal of success in terms of user adoption, having already passed the 100 million downloads milestone, according to the open source browser vendor’s count.

In this regard, there will be quite a few those that make the jump to Firefox 4.0.1.

Along with the release of Firefox 4.0.1, Mozilla is also tending to users that are still running older versions of Firefox.

Firefox 3.6.17 and Firefox 3.5.19 are also available for download to customers running the browser on top of Windows, Mac OS X or Linux.

Firefox 4.0.1, Firefox 3.6.17 and Firefox 3.5.19 are part of the company’s normal update cycle, refreshes designed to kick up a notch security and reliability.

“As always, we recommend that users keep up to date with the latest stability and support versions of Firefox, and encourage all our users to upgrade to the very latest version, Firefox 4.0.1,” revealed Christian Legnitto, Firefox release manager.

Mozilla is also advising users to dump Firefox 3.5 and make the jump to a more recent release of the browser, either Firefox 4.0.1 or at least Firefox 3.6.17.

“We strongly recommend that all Firefox users upgrade to these releases. If you already have Firefox, you will receive an automated update notification within 24 to 48 hours,” Legnitto added.

The reason for this is rather simple, and it has to do with Firefox 3.5 reaching end of life. Specifically, Mozilla does not plan to provide any additional updates for Firefox 3.5 after Firefox 3.5.19. “This is the last planned security and stability release for Firefox 3.5,” Legnitto underlined.

Users that upgrade to Firefox 4.0.1 will soon enough get the chance to upgrade yet again, to Firefox 5. According to Mozilla’s current plans, Firefox 5 is slated for general availability on June 21, 2011.

Firefox 4.0.1 for Windows is available for download here.

Firefox 4.0.1 for Linux is available for download here.

Firefox 4.0.1 for Mac is available for download here.

Firefox 3.6.17 and Firefox 3.5.19 for Windows are available for download here.