For Haskell, there is no doubt it could do better. The culprit is probably the relatively new Websocket server. For evidence, I cite http://www.yesodweb.com/blo

For Haskell, there is no doubt it could do better. The culprit is probably the relatively new Websocket server. For evidence, I cite http://www.yesodweb.com/blog/2011/03/preliminary-warp-cross-language-benchmarks http://www.yesodweb.com/blog/2011/03/preliminary-warp-cross-... But "Not bad for 3 lines of code" is a pretty fair sentiment. Erlang and Go doing great is no surprise. Java didn't do too well, but the implementation didn't really use the most performant tools available. The real loser here is Node.js. Nearly as long as the Java example, but the worst performer in the real metrics. So much for "making concurrency easy."