Is Zimbra really different?

Zimbra is the San Mateo start-up that is taking on Microsoft with its new open-source AJAX-filled email platform. But how is it different from their competitors? Silicon Beat says that “Zimbra has a free version for individuals who don’t want to make money from it, but… its main purpose is to sell to large companies that are already using competing products such as Microsoft.” Silicon Beat also have a first look at Zimbra e-mail here.