Does https://webrtc.googlesource.com/src not count?
One common desired use case is using WebRTC for p2p torrent communications. Right now the best way to do this is in browser, or to use an Electron app that can bridge the WebRTC clients with the standard desktop torrent clients.
It still leaves you writing in c++, but it lets you build a self contained server without any browser stuff. There also were java bindings which is what I used when I was experimenting with it. You just have to build your .so and .jar files.
EDIT: Here's some scala code that I wrote that uses the native bindings. (Please forgive the messy test project that I have abandoned).
https://github.com/jgrowl/livehq/blob/master/media/src/main/...