Last week, we offered Firefox 2 (yes 2!) users a Major Update offer to Firefox 3.0.15. This was despite our official End Of Life for Firefox 2 way back in December 2008.

While most attention is naturally focused on new releases, and on new security releases, there were 5.3% of our users still using Firefox 2. Those users were not getting new fixes and features; even worse, these users were all using versions of the browser that had known, published, exploits – exploits that were already fixed in later supported releases of Firefox.

The previous major update offer was intentionally left available, so any FF2 user who did manual CheckForUpdates would get upgraded to FF3.0.6. However, few did. As most of these Firefox2 users were on FF2.0.0.20, they were obviously willing and able to upgrade when security releases prompted them to. It seemed worth the effort to prompt them again, with a new Major Update offer, and see how many would upgrade.

In the first 7 days after publishing those new major update snippets, 16% of FF2 users have upgraded. Its a slower rate of upgrading then we get for normal security releases. However, its still a significant amount, and its great to see those users get back onto supported, more secure, releases. I’ll continue to monitor uptake, and keep you posted.

(ps: It was really cool that nthomas and abillings were able to find the time to squeeze yet another release into the schedule in the midst of all the releases for FF3.0, FF3.5, FF3.6 beta/RCs and Fennec beta/RCs. To keep this work quick and safe, we did a FF2->FF3.0 MU offer, rather then attempting FF2.0->FF3.5, which would require a bigger testing cycle, details in . On behalf of those users who are only now discovering the Awesome Bar, our faster performance and all the new JIT work, I thank you both!!)