These ebuilds come from https://github.com/yporti/overlay.
If you have some problems, go to the official site first.
skychart-bin : Free software to draw sky charts ( http://www.ap-i.net/skychart/ )
virtualmoon-bin : Virtual Moon Atlas Pro ( http://www.ap-i.net/avl/en/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a yporti
For Paludis use this rsync : rsync://gentoo.zugaina.org/yporti-portage
If you have a problem : ycarus(-at-)zugaina.org