The [Signal Server repository](https://github.com/signalapp/Signal-Server) hasn't been updated since April 2020. There are a bunch of links about this [here](https://libredd.it/r/signal/comments/lw5u2q) but I found [this thread](https://community.signalusers.org/t/15068/49) the most interesting. To me, this is unforgivable behaviour. Signal always positioned themselves as "open source", and the Server itself is under the best license for server software (AGPLv3 -- which raises questions about the legality of this situation). Signal's whole approach to open source has constantly been underwhelming to say the least. Their budget-Apple attitude (secrecy, i.e. "we can never engage the community directly", "we will never merge/accept PRs", etc) has lead to its logical conclusion here, I guess. I have been somewhat of a "Signal apologist" thus far (I almost always defend them & I think a lot of criticism they get it very unfair) but yeah I'm over Signal now.