just a fun hobby project to learn webrtc and p2p networking:

loads a real goldsrc .bsp map file (the same format half-life and cs 1.6 used), parses it in javascript, rebuilds the geometry for webgl with three.js, and runs a from-scratch reimplementation of valve's player movement so the surf feels right. multiplayer is peer to peer over webrtc with no game server.

it uses trystero, which does webrtc peer to peer and uses public relays only to introduce peers to each other, no game server in the middle. everyone in the same room name shares a session, broadcasts their position about 20 times a second, and you see each other surf.