Sorry, your definition of "concurrent" is all over the place. Ruby doesn't have "built in concurrency"? Ruby has fully native threads; it just has the GIL that

Sorry, your definition of "concurrent" is all over the place. Ruby doesn't have "built in concurrency"? Ruby has fully native threads; it just has the GIL that blocks for IO (but you could use jRuby). It gives you several options for message passing. You also have the extremely under-rated dRuby system. Not to mention the whole EventMachine world. Node is "close" to concurrent? It's god damn single-threaded! At the very least it's possible to spawn multiple processes and communicate over a Unix socket, good luck doing something like that with PHP. What does socket.io have to do with anything? Sorry man, I'm hearing a lot of cargo cult opinions and precious little data to back it up.