It's open source, but Moxie has said he doesn't want federation. I don't think he'd be okay with someone writing a third-party client, for example.

He doesn't, but only because of the maintenance burden that would bring: https://github.com/LibreSignal/LibreSignal/issues/37#issueco...

I'm sure if a third-party client would contribute to support the maintenance (both financially and in terms of the time and effort investment) he might be open to that, but obviously that's not going to happen.

Sure, burden. Like say, Pidgin is a burden to [x network]. Not allowing 3rd party is bad, it always is. It takes away choice.

Federation is a completely different story from a third-party client.

Open Source, relies only on Twilio, AWS, GMC, and Apple Push. https://github.com/signalapp/Signal-Server/blob/master/confi...