gtk+ : Gimp ToolKit + ( https://www.gtk.org/ )
libva-vdpau-driver : VDPAU Backend for Video Acceleration (VA) API ( http://www.freedesktop.org/wiki/Software/vaapi )
vte : Library providing a virtual terminal emulator widget ( https://wiki.gnome.org/Apps/Terminal/VTE )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a ennui
For Paludis use this rsync : rsync://gentoo.zugaina.org/ennui-portage
If you have a problem : ycarus(-at-)zugaina.org