evolution-data-server : Evolution groupware backend ( https://wiki.gnome.org/Apps/Evolution )
evolution-ews : Evolution module for connecting to Microsoft Exchange Web Services ( https://wiki.gnome.org/Apps/Evolution )
Add an ebuild in portage :
The ebuild is now in the portage tree.
You can also use layman : emerge layman then layman -a xwing
For Paludis use this rsync : rsync://gentoo.zugaina.org/xwing-portage
If you have a problem : ycarus(-at-)zugaina.org