Zimbra Collaboration is available in two server product editions: Zimbra Open Source Edition and Zimbra Network Edition (which can be served for End Customers as a Professional or Standard)
You can also download the Zimbra edition comparison and Zibmra products overview here :
Zimbra Network Edition is available for on-premises deployment in Professional and Standard Editions. Standard Edition comes with powerful features to support multiple businesses.
Zimbra Professional Edition provides Archiving and Discovery feature that enables you to archive messages that were delivered to or sent by Zimbra Collaboration and to search across mailboxes.
Zimbra Collaboration Open Source Edition is available free for download. It allows you to test, evaluate, deploy, customize and improve and there is a vibrant Open Source Community supporting it.
|Offline Web Client|
|Advanced Search Builder|
|Zimbra Contacts Features|
|Zimbra Calendar Features|
|Zimbra Desktop Clients|
|Zimbra Mobile Devices|
|Zimbra Server Admin|
|Zimbra Domain Management|
|Zimbra Network Edition|
|Zimbra Suite Plus|