Personally, I think Cramp's interface is a lot better than Goliath when it comes to streaming, because everything is streaming in Cramp. YMMV. https://github.com/lifo/cramp/blob/master/examples/sse/serve... in case you want to compare. Also, goliath websockets branch looks outdated.

FWIW, I do like Goliath. More async solutions in Ruby the better!