GeneralSync will support Thunderbird 102 and is now available completely free-of-charge. Whether the project will survive depends on your support.
Your generous support (though still not even covering the costs for keeping the lights on) convinced me to do commercially questionable things: the project went further into debt to bring you support for Thunderbird 102! For Thunderbird users, it is thus likely that GeneralSync will remain useable for at least another year.
In other news I finally disabled all paid licenses: GeneralSync is now officially free-to-use. I am considering further options towards releasing some or all of GeneralSync under open source licenses, but there is no timeline for that decision yet. Either way, I continue to hope that the project can eventually survive on voluntary payments, potentially with a larger user base now that GeneralSync became more accessible due to the lack of a price tag.
Again, thanks for all existing supporters, as well as everyone that will support the journey in the future!
Happy syncing!
PS: There is no documentation on Thunderbird 102 yet, and I'm not sure if I will get to that in time. Expect significant changes in the address book – some lesser used features were removed (like the four custom fields, the data will still be there, but you cannot access it anymore), while many were added (finally a unlimited number of email addresses!). Also note that GeneralSync does not yet support the new anniversary and timezone fields, though that might change in a later version.