Hacking Heroku with Custom Build Packs

I came across this Io (http://www.iolanguage.com) Heroku buildpack a few days ago: https://github.com/freeformz/heroku-buildpack-io

Disclaimer: I haven't tested it (I'm not a Heroku user... yet!).

The reason it is a little known fact is because Heroku tells people: "This is still a bit of an alpha so please don't tweet/blog/etc about it yet."