[adapter.js] is a shim to insulate apps from spec changes and prefix differences. In fact, the standards and protocols used for WebRTC implementations are highly stable, and there are only a few prefixed names. For full interop information, see webrtc.org/web-apis/interop.
bower install webrtc-adapter
npm install webrtc-adapter-test
Inclusion on Browser
Copy to desired location in your src tree or use a minify/vulcanize tool (node_modules is usually not published with the code). See webrtc/samples repo as an example on how you can do this.
Head over to test/README.md and get started developing.