Welcome to the forums,
The sourceforge site is no longer in use as of 4.5.7, we've switched to a perforce repository.
Connection directions to get the source are listed in
Building Zimbra using Perforce - Zimbra :: Wiki >
Franklin README - Zimbra :: Wiki
(Then you need to look at //depot/zcs/FRANKLIN/ZimbraOffline/ - the FRANKLIN branch is currently 5.0.5/.6)
Zimbra Desktop is a browser based offline-capable client.
-It can be used against a Zimbra server (best experience!) or with any other IMAP/POP service (it also included defaults for connecting to ymail, gmail, aol, etc).
The Zimbra Collaboration Suite refers to the
server &
web-client combo, available in open source and network editions with more features - you can compare here:
/products/product_editions.html
That's some pretty big differences you'll need to understand - are you sure you don't want to get started with a pre-compiled binary first?