Alex Keybl has made a post to announce the end of support for the Firefox web browser 3.6 as of April 24th. We know a lot of people who prefer the older versions before Firefox got a little bloated but if you are using 3.6 this would mean that they will not be updating it and new security holes will be a possibility. Check that; likely. In other words, this is a good time to upgrade your old Firefox to a newer version .

They are also reducing support in the 13x versions to Windows XP Service Pack 2 minimum. This mostly eliminates anyone silly enough not to be updated to the latest XP service packs and Windows 2000 users.

"After two years of regular updates, we’ll end our support for Firefox 3.6 on April 24th. In the years since Firefox 3.6, we’ve make incredible improvements to Firefox, including phenomenal HTML5 capabilities, Firefox Sync, faster java script  performance, support for the Do Not Track header, and an easier, quieter update process. Barring any major stability or security issues found over the next few weeks, Firefox 3.6.28 will be our last 3.6 release.

We strongly advise our users to upgrade from Firefox 3.6, as they will no longer receive critical security updates as of April 24th. In support of Firefox 3.6 users in organizations, we’ve delivered on our promise to implement the Extended Support Release plan three months ahead of ending support for Firefox 3.6. Enterprises and organizations should complete qualification and deployment of the ESR over the next month.

We’d also like to take this opportunity to announce that our minimum supported Windows version will change from Windows 2000 to Windows XP SP2 in Firefox 13. We never change minimum requirements lightly, but this support change allows us to significantly improve Firefox performance on Windows by using a more modern build system. Windows XP users are advised to update to the latest service pack, and Windows 2000 users should consider upgrading ahead of the June release of Firefox 13."