Yes, core.async should definitely be mentioned. It's also much more than a nice channel-based system, but you have to dive in to appreciate how good it is. For example, you have to write real systems to appreciate the fact that core.async channels can be used both from "go-threads" and real threads. That's really useful when your async work involves both quickly sending responses to clients (where lightweight go-threads shine) and doing heavy I/O for database updates (where you want a thread to pick up the work). You use the same channels for all types of work, which is really neat.