Naven
Glossary
WebRTC
The browser technology that carries voice and video between people without a plugin or an app.
Built into every modern browser, WebRTC opens a direct media connection between two devices where the network allows it, falling back to a relay where it does not. It is why a video call can happen on a web page at all, and why it needs no install.
It handles the hard parts — echo cancellation, jitter buffering, adapting the bitrate to a bad connection — and exposes them as an ordinary JavaScript interface.
Where Naven stands
Naven's voice and video calls are WebRTC, which is the reason there is nothing to download on either end of a call. A managed device that forbids installs can still make one.