Doki_pen-overlay is a project mainly written in Ruby, it's free.
My personal gentoo overlay
h1. doki_pen's Overlay
h2. Layman (the easiest way to stay up to date)
pre. $ emerge -av layman $ layman -f -o http://github.com/dokipen/doki_pen-overlay/raw/master/doki_pen-layman-list.xml -a doki_pen