"Zimbra is out today with the first major release of its open
source based Zimbra Collaboration (ZCS) solution since being
acquired by Yahoo last year. Zimbra's ZCS release also comes at a
particularly interesting time as Microsoft bids for ownership of
"ZCS 5.0 extends the feature set of ZCS and also introduces
integrations with Yahoo products as Zimbra ramps up to compete
against Microsoft Outlook and Exchange..."