In this latest State of the Thunder, we're discussing the upcoming yearly ESR, 140.0, which is due out June 24, 2025. We explain our numbering convention and our different channels, which comes from Firefox, and the difference between ESR, Release, Beta, and Daily. Find out why we're encouraging to use the monthly Release channel, but how this won't take anything away from ESR. Learn more about what channel is right for you (especially if you use add-ons), how to help us with using Beta and Daily, and how to safely move between ESR and Release. And as always, we finish with a community shoutout!

00:00 Intro 01:39 What is ESR? 05:01 How to keep track of channels? 10:05 How to check which channel you're running 11:25 Why the push for the monthly Release channel? 18:22 Why is it called Release channel and not Monthly Release? 21:05 ESR support expectations 24:49 How stable is the Beta channel? 29:03 Can I change channels through a simple update? 33:12 Add-on support in the Release channel 38:53 Highlights of ESR 140 44:41 Community highlight

Resources: What Train is It Now: http://whattrainisitnow.com/ Monthly Release Channel: https://blog.thunderbird.net/2025/03/thunderbird-release-channel-update/ Choosing a Release Channel: https://support.mozilla.org/kb/choosing-thunderbird-release-channel Testing Beta Support Article: https://support.mozilla.org/kb/thunderbird-beta Testing Daily Support Article: https://support.mozilla.org/kb/thunderbird-daily Release Channel Support Article (with info on safely downgrading): https://support.mozilla.org/kb/thunderbird-release Add-on Compatibility Add-on: https://addons.thunderbird.net/thunderbird/addon/addon-compatibility-check/ tilorenz's Calendar grid patch: https://phabricator.services.mozilla.com/D251992