arcan : Arcan is a powerful development framework for creating virtually anything from user interfaces for specialized embedded applications all the way to full-blown standalone desktop environments. ( https://arcan-fe.com/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a psix-overlay
For Paludis use this rsync : rsync://gentoo.zugaina.org/psix-overlay-portage
If you have a problem : ycarus(-at-)zugaina.org