at-spi2-atk : Gtk module for bridging AT-SPI to Atk ( https://wiki.gnome.org/Accessibility )
caribou : Input assistive technology intended for switch and pointer users ( https://wiki.gnome.org/Projects/Caribou )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a gnome-next
For Paludis use this rsync : rsync://gentoo.zugaina.org/gnome-next-portage
If you have a problem : ycarus(-at-)zugaina.org