What features don't we want (yet)?
There are a number of common features that we aren't going to implement. They are important parts to many chat applications, and could certainly be added to what we we're building here, but would detract from the main points.
Chat channels are an incredibly common feature that we won't be implementing. It is extremely unusual to see a chat server without separate channels for conversations, but in this case the cost of added complexity in the front end is not sufficiently offset by the value of what we would learn implementing the backend aspects.