Today we shipped the first version in the new 153 ESR series, Betterbird 153.0esr-bb6. At the moment, this is only available for Windows, in a few days, we'll offer binaries for for Linux and Mac. We'll see how stable this series turns out to be and when we will start promoting it as the new primary version superseding version 140.
We've analysed available bug fixes for Thunderbird carefully and we're shipping 32 fixes and features that the Thunderbird folks are so far not including in their 153 ESR series.
On top of the 32 extra fixes and features, Betterbird has another 220 improvements. We're happy to report that we just concluded an AI review of all patches and address the minor issues found before this release. Of course the current 140 ESR series will also be updated when 140.13.0 ships in the next few days, whenever the Thunderbird folks are ready.
Like always, everything is documented in the Release Notes.