Pasting services works great when you need to share trivial code that can be “executed” in mind. But wait, are’t computers that who should execute code? JSFiddle doing a great job of running javascript code and present you with result. Same is doing CIBox, but for server-side languages, Ruby, Python, Node.js … others to come later. And that’s not all about. It does not just run Ruby/Python/Node. It does run various versions of them. So you can test your code against all major language versions.

Starting from here, nothing can stop you to upload your apps/libraries(via rsync or github) and test/build them just as you do on your computer. How? Simple. There are an realtime terminal(with history, completions etc.), a handy file manager and a classy file editor. See it in action. And yes, it is Open Source