Interesting, I've been using it for a couple of months (this and pianobooster). It works quite well but there are countless improvements one could make. It is open source as well, but the software is written in an obscure language. ('moonscript').

MoonScript isn't too obscure. It's to Lua as CoffeeScript is to JavaScript. I personally think it's a nice improvement over Lua. (Except for the use of backslashes...)