calf : A set of open source instruments and effects for digital audio workstations ( http://calf-studio-gear.org/ )
hyperion : An opensource 'AmbiLight' implementation (next generation) ( https://hyperion-project.org/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a gerislay
For Paludis use this rsync : rsync://gentoo.zugaina.org/gerislay-portage
If you have a problem : ycarus(-at-)zugaina.org