SuSE OpenExchange is actually two things: an OpenSource messaging server
based on Cyrus and OpenLDAP and a closed source, proprietary
web groupware server (ComFire).
<br /><br />
OGo is very similiar to the groupware server part
(German users can check the
<a href="http://www.linux-magazin.de/Artikel/ausgabe/2001/12/kommerzgroupware/komm.html" target="extlink">Linux Magazin article</a> on that)
and indeed you can install OGo as the groupware component on an
OpenExchange server to save the ComFire license costs and use a solution
wholly composed of OpenSource software.