consolekit : Framework for defining and tracking users, login sessions and seats. ( http://www.freedesktop.org/wiki/Software/ConsoleKit )
polkit : Policy framework for controlling privileges for system-wide services ( http://www.freedesktop.org/wiki/Software/polkit )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a gmt
For Paludis use this rsync : rsync://gentoo.zugaina.org/gmt-portage
If you have a problem : ycarus(-at-)zugaina.org