These ebuilds come from https://github.com/anyc/steam-overlay.
If you have some problems, go to the official site first.
steam-client-meta : Meta package for Valve's native Steam client ( http://steampowered.com )
steam-games-meta : Meta package for Steam games ( http://steampowered.com )
steam-launcher : Installer, launcher and supplementary files for Valve's Steam client ( http://steampowered.com )
steam-meta : Meta package for Valve's Steam environment ( https://steampowered.com )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a steam
For Paludis use this rsync : rsync://gentoo.zugaina.org/steam-portage
If you have a problem : ycarus(-at-)zugaina.org