It's call a REPL and any decent programming language has one. Instead of creating a project; a new directory, a build script, manifest file, etc. all you have t

It's call a REPL and any decent programming language has one. Instead of creating a project; a new directory, a build script, manifest file, etc. all you have to do is type an expression at the repl and have it evaluated immediately. You couldn't "tweet" code because tweeting has a longer response latency than a REPL; you're waiting for a human twiteratus douchebag to write back or acknowledge your existence. But the repl makes up her mind in an instant, so you're hooked in a far more enjoyable, not to mention far more enlightening dialog than you could ever have on twitter. Try it: telnet prompt.franz.com 23 (look, an odd-ball question deserves and odd-ball answer, alright)