The Signal Server repository hasn’t been updated since April 2020. There are a bunch of links about this here but I found this thread 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.
qTox
qTox is just a desktop client. The Tox protocol implemented by c-toxcore is the one with security issues. BTW, part of the issue is precisely that the Tox protocol is not an e2ee one, and in one of the issues referred the axolotl protocol is shown as an example… So, no matter the client, the Tox protocol is lagging behind in terms of security.