Zimbra Collaboration Suite or ZCS is a groupware product from Zimbra Inc, Palo Alto, California, USA. The company was purchased by Yahoo in 2007 and subsequently by Vmware in January, 2010.
ZCS is much more than just a email and calendar server. It provides document storage and editing, instant messaging and simplified administrative controls in a webmail user interface built with the latest Ajax web technology.
ZCS offers more options than any other platform to meet various application deployment strategies, including on premises or hosted email, which can be cloud and virtualization infrastructure.
To know more about the products please visit http://www.vmware.com/products/zimbra/overview.html or http://www.zimbra.com/