virtualbox : Family of powerful x86 virtualization products for enterprise as well as home use ( http://www.virtualbox.org/ )
virtualbox-guest-additions : VirtualBox kernel modules and user-space tools for Gentoo guests ( http://www.virtualbox.org/ )
virtualbox-modules : Kernel Modules for Virtualbox ( http://www.virtualbox.org/ )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a nigoro-fbsd
For Paludis use this rsync : rsync://gentoo.zugaina.org/nigoro-fbsd-portage
If you have a problem : ycarus(-at-)zugaina.org