There has been a lot happening this week with Thunderbird and a result a lot of activity on this blog recently. Here is a brief summary of what has happened so far:

•     Thunderbird 3.1.18 Released
•     Thunderbird 10.0 Released
•     Thunderbird ESR (10.0.0) Released
•     Thunderbird 3.1.x support ending April 24, 2012
•     Mozilla-Central (Firefox Nightly) Channel moving to MSVC2010 / No more support for Windows 2000 or Windows XP RTM/SP1 (Firefox 13+)

As promised, more information on the Thunderbird ESR. Thunderbird ESR was created to address concerns with the current Rapid Release Process by Enterprise Users. The first Thunderbird ESR 10.0.0 (Mozilla may be dropping version numbers in the future, more on that a bit) was released on January 31st, 2012. The next update…yes, there are still going to be updates for stability and high/critical security issues…will be in six-weeks. On March 13th, 2012 the main Thunderbird will move to version 11 and the ESR will move to 10.0.1 on this date. This process will repeat every six-weeks (just as it has been since Thunderbird 6). However, on August 28th when Thunderbird 15 is released ESR version 17 is going to available on the ESR Aurora channel. This will move to the ESR Beta channel on October 9th when Thunderbird 16 comes out. November 20th, Thunderbird 17 is going to be released along with ESR 17.0.0. There will be one final ESR release under the 10.0.x branch (January 2nd, 2013) and then the branch will be retired on February 12th, 2013.

Release Schedule Page

Now as mentioned earlier, the incremental (10.0.1, 10.0.2, etc) releases will only have stability updates along with high and critical security updates. This means there is not going to be much difference between ESR 10.0.0 and ESR 10.0.7 or 10.0.8 feature wise. However, there is going to be a major changes between ESR 10.0.7 and ESR 17.0.0 as everything that had been added from Thunderbird 11 to Thunderbird 17 is going to be incorporated into this ESR release.

Some folks are wondering ‘Is Thunderbird ESR is suppose to be a replacement for Thunderbird 3.h?’. That question is hard to answer. The short answer is yes…sort of. It is a replacement for 3.u in that this branch is going to see long term (1-year versus six-weeks) maintenance updates. Does this mean Thunderbird 3.6 users should move over to the ESR? No, ESR is designed for Enterprise Users or organizations that have issues with the six-week release cycle. Further some 3.1 users, mainly those running older version of Windows (95, 98, Me and older versions of NT/Server) and Mac OS X are not going to be able to move over. Those running Windows 2000 and XP RTM/SP1 along with the older versions of Mac OS X can move over, but will not be able to update to ESR 17.0.0 come November 20th, 2012 (more about this later). If the user can, they really need to move to the main Thunderbird 10. The sooner the better as it is going to be quite a change going from 3.1 to 10.0.0 and will just be more so if they wait until Thunderbird 11 or 12. Also remember ESR releases are only going to have security and stability updates (much like Thunderbird 3.6 since last April with the release of Thunderbird 4)

The numbers mean nothing..okay may be not, but that is Mozilla’s plan. Like Chrome, they are working on getting a ‘silent update’ (no UAC or user prompts) mechanism in place. When a new version of Thunderbird is released they will automatically (if they have elected to keep auto updates active) behind the scenes on the next restart. When going into Help > About Thunderbird, there will not be a version number showing (though I am sure the User Agent is going to reflect a ‘version’ number) and they are not really even going to be aware that they are a new version unless there some changes to the UI.

Bye, bye Windows 2000 and Windows XP RTM/SP1 users. Mozilla is in the process of moving the Mozilla Central (Firefox Nightly) channel builds (currently Firefox 13) on to Microsoft Visual C++ (MSVC) 2010 as the current builds are getting too close to the size limit for MSVC 2008 to be able handle. Actually, towards the end of last year the nightly builds had to be suspended for a couple days and ‘cleaned up’ to get them under the size limit. The compiler engine in MSVC 2010 does not support Windows 2000 or Windows XP RTM and SP1. While this was mentioned back in early July there really hasn’t been much feedback/discussion/announcements about this in the past nearly 7 months. Mozilla is not even certain how much of their user base is still on Windows 2000, much less Windows XP RTM/SP1. As for Thunderbird, it is uncertain when these users are going to be “abandoned”. At this time Comm-Central (Thunderbird Daily) builds will continue to use the MSVC 2008 compiler engine. Also, Thunderbird ESR 10.0 will continue to support Windows 2000 and XP RTM/SP1 past the future ‘drop-date’ for the regular Thunderbird releases.

More info will be posted once Mozilla Messaging decides how they want to handle the Thunderbird builds.