Have you not tried searching yourself? There are quite a few. Bitmessage, Tox, Wire, Matrix. Even Signal offers a desktop app, but it needs a phone number to

Have you not tried searching yourself? There are quite a few. Bitmessage, Tox, Wire, Matrix. Even Signal offers a desktop app, but it needs a phone number to register. https://en.wikipedia.org/wiki/Comparison_of_instant_messaging_clients#Secure_messengers https://en.wikipedia.org/wiki/Comparison_of_instant_messagin... Perhaps you're referring to the fact that there's no 'standard' solution. This is the way of things, it seems - network effects weaken as choice increases.