action-coding : Ruby + Processing ( http://code.google.com/p/action-coding/ )
processing : an open source programming language and environment for people who want to program images, animation, and sound ( http://processing.org/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a matsuu
For Paludis use this rsync : rsync://gentoo.zugaina.org/matsuu-portage
If you have a problem : ycarus(-at-)zugaina.org