The developers of the popular mail client Thunderbird recently announced a change in their approach to forming significant releases. Instead of the current annual release model based on Firefox ESR vehicles, Thunderbird will be moving to a monthly release cycle starting in March 2025. These significant releases will now be based on regular Firefox releases with the typical support period.
Since October of last year, Thunderbird has been experimenting with assembling releases based on standard Firefox issues. However, these assemblies have not been made available to users as they were intended for testing purposes only. The latest stable release of Thunderbird, version 128, was released in July. Moving forward, only corrective updates for the 128.x branch will be issued each month. In March, Thunderbird 136 will be released to the public for testing without any specific designation.
This shift to a monthly release schedule aims to accelerate the introduction of new features, ease the transition to new releases, and increase the number of bugs addressed with each update. Previously, only vulnerabilities and major issues were addressed in ESR releases. Thunderbird currently boasts 10.5 million active installations, and developers hope to see a 20% increase in active installations of monthly updates by the end of the year. The current share of Thunderbird assemblies based on standard Firefox releases is 0.27% (29543).
For more information, you can visit the Thunderbird announcement and check out the latest releases on their website. Additionally, you can view Thunderbird’s project statistics to learn more about their user base and update progress.