As someone who has done some work with WebRTC (attempting to build a video conferencing app for work) it's hard to boil things down to a "Hello World" due to th

As someone who has done some work with WebRTC (attempting to build a video conferencing app for work) it's hard to boil things down to a "Hello World" due to the whole ICE and signalling thing. It's unfortunate, but in order to get this client-side peer-to-peer thing working, you need to have a server in the cloud (i.e. not behind NAT) that can pass signals between the two peers. The tutorials other people have linked to look good, just note that unless you're talking between 2 computers within your local network (and even then you'll have to copy-paste their IP addresses to each other), you'll need to either deploy a server or use a 3rd party library like PeerJS that uses one. I hope that eventually IPv6 will obviate the need for NAT and make this whole thing much simpler, but until then, this is what we've got.