Firefox users do have the option to disable automatic updates, but they’re on by default. The typical reluctance of enterprises to upgrade software without ages of testing has been the bane of software progress for quite some time (part of the reason why IE 6 is still alive). It could possibly be an effect of the upgrade process not being automated effectively, or perhaps enterprise users are to blame. The bad news is that there is now a good-sized portion of users who are not following along from one version to the next in this new release schedule that Mozilla started with Firefox 5 in June. At the current rate of change, they will be down to around 8% in a year. Now, five months later, those older versions are down to representing “only” 28%. Early in June they accounted for 43% of all Firefox usage. The good news is that the “legacy” versions of Firefox – those being version 3.6 or earlier – represent a rapidly diminishing portion. In case you’re wondering, the vast majority of the “3.6 or older” bracket is made up of version 3.6. Note that this is at the later part of Firefox 7’s six-week cycle as the latest release version, so browser users should have had plenty of time to upgrade – or rather, be upgraded. Here’s the distribution of Firefox versions for the final week of October 2011, as measured by StatCounter. Next November, the latest version will be Firefox 16.

Remember, at the current pace we’ll see at least eight new Firefox versions per year.

So imagine the effect of this kind of “left-behind” retention in the long run. To give you an example, Firefox 5 was the first version in this rapid release schedule and should be history by now, but it still clings on to almost 4% of the Firefox user base.

There’s a long tail of older versions starting to form, and over time this may accumulate enough version fragmentation that it could become a real problem. For every new version of Firefox that Mozilla releases, a fraction of users are for whatever reason not being upgraded. On Tuesday, November 8, it’s already time for the release of Firefox 8.īut there are clouds on the horizon. Mozilla’s new, rapid release schedule for Firefox calls for a new version every six weeks. Mozilla’s development pace for Firefox went into overdrive this year, as they adopted a strategy similar to that which Google uses for the Chrome web browser.

Firefox previous versions