On Node.js you have https://github.com/js-platform/node-webrtc and https://github.com/vmolsa/webrtc-native which are a bit unstable, or https://github.com/mappum/electron-webrtc which works fine but requires running an Electron process.

You can directly use the official WebRTC libraries (https://webrtc.org/native-code/development/). https://github.com/Lalaland/DataChannelServer is a wrapper I worked on last summer to make it a bit easier (not complete by any means, but it at least gives you a sense of how the API works).

Haven't tested it yet, but OpenWebRTC [1] has been on my radar for some time now.

1. https://github.com/EricssonResearch/openwebrtc