I don’t understand where this energy that signal doesn’t want 3rd party clients is coming from.
Their open source code is permissive of commercial forks.
Like, if their goal was to block third-party clients, then they would look more like Facebook or Reddit
Under Signal's original leadership, there was definitely a hard stance against third party clients connecting to the network. I think they've been quiet on third party clients since Moxie left.
I think they wouldn't want a third-party client to become mainstream. That a few people bridge matrix to signal is not exactly a problem.
Software license ≠ terms of service.
They can give you the right to reuse their source code for building your own service using your own network (an aspire to give you this right), but still forbid you to connect to their service on their network with third party clients.
In practice, they don't seem to enforce that a lot (anymore).
It's unlikely that their ToS would be enforceable in court. The fact that Apple never tried to sue Beeper speaks to this.
It doesn't necessarily go to court. In the past, there was a project that was a light fork of Signal, LibreSignal, that was Signal but without the google libraries. They have asked the developers to stop distributing a version of it that connected to their network, and the developers stopped the distribution.
I guess they didn't do so for Molly. I suppose a lot of water has passed under the bridge.
You can totally fork their projects! You just can't call yours "Signal" (trademark I guess?) and you can't connect to their servers. Molly seems to be tolerated, somehow? Maybe because it is niche.
But clearly connecting to the Signal servers with an outdated, modified fork is against Signal's goal.