Membrane [1] is a project that aims to create a pipeline-based media framework, much like GStreamer, but more to the point (smaller scope) and written for the Erlang VM. We could foresee a WebRTC module existing at some point in the future, but right now the project seems to be just in its infancy.

I found it while dreaming about writing an Erlang-based WebRTC media server like Kurento, for which this kind of frameworks are invaluable, and currently GStreamer is the king.

[1]: https://www.membraneframework.org/