Future of Lightning support for TB 1.5

After reading the notice at the top of http://www.mozilla.com/en-US/thunderbird/all-older.html that as of today TB 1.5 will no longer be supported, I was thinking whether it would make sense to drop support for the TB 1.5 series after the 0.7 release.

I see the following reasons for this:

  • As the TB 1.5 core code is pretty old, it hurts in a variety of places. See bug 330121, bug 351997, bug 389384 or bug 397920 for examples
  • We have a very small team of core developers. And testing changes on TB 2, TB 1.5 and Sunbird puts a great burden on their shoulders. Dropping TB 1.5 from the requirements list would ease that burden
  • Our testing community uses TB 2 almost exclusively, so TB 1.5 specific bugs are often found very late if ever
  • Most Thunderbird users will probably already have made the switch to TB 2. So we wouldn’t lose lots of users here

I would be interested in hearing your feedback on this.


  1. Yes I think you should drop it. You shouldn’t spend your time trying to support old applications.

  2. Yes, the world is going ahead so I think there’s no meaning to spend resources on an outdated version. And maybe this would be an additional point to make people update their apps to a safer, faster and newer one.

  3. totally agree. thunderbird is free, and easy to upgrade. NO reason to struggle with 1.5 issues in lightning.

  4. Dropping it sounds like the right thing to me.

  5. absolutely agree. only gotcha would be that right now palm users are tied to 1.5, as there is no palmsync for 2.x
    this is really not your fault though, and you can’t be asked to cover slow movement elsewhere.
    anyone from palmsync out there? would love to hear an update

  6. yes I agree, thunderbird is at and seems very stable. Even though I have a Palm I have moved on. :-)

  7. Thunderbird is an evolving product, there’s no good reason why anybody should be using 1.5 anymore. No sense in the Calendar devs wasting their time to support TB1.5 only because end users are too lazy to upgrade.

  8. Drop it. Better use ressources to move forward ligthning.

  9. Andre Mueninghoff

    Dropping TB1.5 makes sense for this type of project. Narrowing a team’s focus often strengthens it and results in higher quality outcomes.

  10. I agree to drop support for 1.5. However some distros (RHEL 5.0 for one, ) still come with TB 1.5. This may have the unfortunate consequence of increasing the 1.5 user base.
    see http://distrowatch.com/table.php?distribution=redhat

  11. I agree; no use supporting a soon-to-be-unsupported product line.
    Since 0.7 is about to be released, it should be the last one supporting TB 1.5, though it would be good to mention something about it in the release notes of the future versions.

  12. Yeahp, I agree with all the previous posts.

  13. I agree, the users that have the foresight to be using Thunderbird let alone lightning are definitely savvy enough to have upgraded to Thunderbird 2 by now.

  14. Drop drop drop!

  15. I think that supporting an unsupported (by Mozilla (or Mailco..)) version of thunderbird would be a strange move. Because the release of Lightning 0.7 after the 18th it is even strange that 0.7 supports 1.5. So drop it.

  16. I see no reason for anyone to still stay on TB1.5. it is so easy to upgrade, so drop it.

  17. if supporting TB1.5 needs any additional time in developing and testing, please drop it!
    it’s better to focus your developing time to current versions of TB than to stick to old versions! so you can better prevent/fix bugs and develop new features or even better usability.

  18. Everyone who blithely says it’s easy to upgrade from Thunderbird 1.5 to 2 and that everyone should have already done it by now appear to be speaking about home user situations.
    Debian 4.0 Etch, released in April 2007, includes Thunderbird 1.5 (AKA Icedove).
    All versions of Ubuntu other than yesterday’s new version 7.10 (versions supported for _years_ yet) include Thunderbird 1.5. (though maybe MoCo will force Ubuntu to upgrade their 6.06 Dapper LTS version to 2.0)
    For users of these and probably other major Linux distributions it isn’t so sensible or desirable to upgrade outside of what their distribution is offering.
    This becomes particularly important in an organisational environment where many desktops are maintained (hundreds, thousands, tens of thousands). Thus you will be denying a significant number of people access to Lightning for some time to come at just the point that Lightning will be taking off. I think this is a shame. It denies me access to Lightning and a proportion of those I provide free software desktops to as part of my job as an enabler of free software solutions to organisations.

  19. I agree, drop it. We have in our enterprise 400 PCs with TB1.5. Lightning will become in the next future our default calendar application. Surely we will than migrate to TB2.0. Thanks for your work!

  20. Pete, as I said in the initial post, we are thinking hard about removing support for the TB 1.5 series *after* the upcoming 0.7 release.
    So our 0.8 release would be the first release where we do not support TB 1.5 any longer. I do not expect 0.8 to come out before January or February 2008, so TB 1.5 will be supported for a few months longer.
    In addition I do not expect us to blatantly break TB 1.5 support even if we decide to officially drop our support for it. The core code for TB 1.5 and TB 2 does not differ significantly and even if we do not support it any longer, one *might* still get Lightning to work on TB 1.5 by tweaking the install.rdf file.

  21. albi’s point is a very good one, however long-lived distributions still have significant time to run, in my opinion (and hope) well beyond the time at which Lightning will become usable.
    Simon, thanks for your response. February isn’t far off in the scale I am considering. How about a Lightning 0.7 branch maintained for 1.5? If it’s likely to be easy to tweak Lightning 0.8+ for TB1.5 then perhaps it’s trivial to have two versions of Lightning available?
    I appreciate the difficulty of the situation – few developers; software not even released yet; TB 1.5 is end-of-lifed by upstream – and can appreciate if you’re not able to facilitate 1.5 support. I just wanted to put my perspective in contrast to the blanket comment coverage thus far that was saying it’s not an issue for people to upgrade Thunderbird. If you’re in any way able to take my angle into consideration to whatever extent you’re able that’d be great.

  22. Pete, as I said we have only limited resources and maintaining another branch just for TB 1.5 would impact those resources and move developer time away from fixing bugs and adding new features for all the other users.
    If this is done, then someone else would have to step up and do it. And just tweaking a config file in future versions of Lightning to get TB 1.5 support is not enough. We also have to take quality considerations into this. If users see such a package coming from us, they would expect the same quality as from the officially supported packages that have been tested by our community. And as the TB 1.5 packages would not be tested in the same manner, this could have serious implications for our outside appearance.
    But as I said, we would be happy to help a person stepping up to do this with advice, pointers in the right direction and infrastructure support (ftp space, dedicated website, etc.) if needed.

  23. I just announced myself that next Adblock Plus release will no longer support Firefox 1.5/Thunderbird 1.5. There is no way to get enough testing for unsupported versions, also I can now rely on Gecko/JavaScript improvements in 2.0 versions. Support is good but only as long as it doesn’t stall development.

  24. drop it like its hot… ;)
    i agree with that. if you are short on resources you should concentrate on progress, especially when its so easy to upgrade from tb1.5 to tb2.
    Keep up the great work! it starts to be seriously good tool, even in buisiness environments! Thanks for that! Im looking forward for locally cached online calendars and device synch!

  25. >> For users of these and probably other major Linux distributions it isn’t so sensible or desirable to upgrade outside of what their distribution is offering.
    If their distribution hasn’t ported 2.x, then it’s effectively a dead distribution. We’re not talking about last week or last month, it’s been 6 months.
    >> organisational environment where many desktops are maintained (hundreds, thousands, tens of thousands)
    Today’s deployment tools have made this painlessly easy. Running the latest software is the easiest and cheapest way to provide the most stable and most secure environment. I’ve worked in shops where software was updated as early as 24hrs after release! Any company who doesn’t install new software (when it’s free) is dragging their feet and deserves a small kick in the pants.
    And let’s be real here, no major company with hundreds of users is deploying Lightning yet since it’s still in the beta phases.
    Thanks for playing devil’s advocate but I’d give your point more credit if Lightning was after version 1.0 or if dropping support applied to a piece of software newer than 6 months old.

  26. I agree, drop support for 1.5.
    Anyone still needing to run lightning on TB 1.5 can always use the .7 release. It should be viable for some time yet.

  27. Drop it. In fact, mention in the release notes that 0.7 will work on 1.5, but use is not supported going forward. That way, any 1.5 bugs in 0.7 can be ignored.

  28. Dropping it sounds to me the best way to use your resources. People should be upgrading to the newest versions possible for multiple reasons. Thunderbird releases are supported for quite a reasonable length of time.

  29. Hmm… After checking my ‘about’ page I realize that I’m still using TB1.5 on the desktop. I’ve had great success with TB2 on my laptop so I’ll make the switch.
    Frankly, I don’t see much of a reason to stay with TB 1.5 so dropping support for it is a good idea. Just find a way to alert users of 1.5 that they are no longer supported.

  30. Just because you aren’t supporting TB 1.5 doesn’t mean users couldn’t continue to use pre .8 releases. Is it possible to download previous releases? I assume it is….just make sure there’s an obvious link so users can download old versions if they need to.
    Wasting resources on software that isn’t supported by the developing company doesn’t make sense. So I totally agree, drop TB1.5 support and move on with the stuff that’s important.

  31. Absolutely. Drop it. It’s legacy. It’s the past. Plan for a future.

  32. AFAIAC you can drop it.

  33. I’m still on Mozilla 1.7.x, the last version where Calendar is/was available.
    Sadly, Seamonkey is not supported by the Calendar Project.
    Maybe you should add some info about Mozilla/Seamonkey on your website.

  34. I disagree because software lifecycle in enterprise is long (~18-24 months) and then, checking and deploying a new version needs large amount of time.
    In great organizations, stability and compatibility are required qualities for pieces of software to be selected.

  35. Laurent, using a 0.7 release is nothing a large enterprise would think about (and rightly so).