All it's doing is opening a file, connecting to other clients and appending the messages between clients to the file. What you're missing is that K automatical

All it's doing is opening a file, connecting to other clients and appending the messages between clients to the file. What you're missing is that K automatically sets up an environment with the necessary pieces in place. A server, the sockets, a type of reactive/eventloopy environment. Everything else is just function call/index/assignment and some mappy/foldy stuff In some ways its the same reason Mathematica seems so magic sometimes.