[larma]

While Dino and all of its dependencies can be compiled and run on Windows and macOS, this process is tedious and GTK isn't really well-tested on anything but Linux, resulting in worse UX when not going the extra mile of doing targeted modifications for these platforms. This hopefully improves with the migration to GTK4.

The XMPP Standards Foundation publishes a document once a year stating a set that decent XMPP clients and servers should implement. The current one, https://xmpp.org/extensions/xep-0459.html even has a specific section on calling (it doesn't cover group calls yet).