I'd like to introduce my young cousin to a bit of programming. Ideally ruby, as that's what I'm familiar with. However finding a suitable text editor is a real pain. All I need of the editor is the ability to type a few lines of code, press 'Run' and get some results (or not, as the case may be). The simpler the editor the better, I don't need Netbeans, Eclipse etc. What I want to avoid is the necessity of using the terminal to run scripts, TextWrangler, Textmate and IDLE for Python can do this. Unfortunately I need something that will work on Windows, or Ubuntu, otherwise I would have just installed Textmate on his laptop.
Any suggestions would be greatly appreciated.