How does OGo compare to SuSE OpenExchange?
SuSE OpenExchange is actually two things: an OpenSource messaging server based on Cyrus and OpenLDAP and web groupware server (ComFire). OGo is very similiar to the groupware server part (German users can check the Linux Magazin article on that) and indeed you can install OGo as the groupware component on an OpenExchange server.