I think someone who is good in Zimbra development or re-coding will be able to clarify this to me, as there are not many resources available regarding this topic.

Is there a way to develop our own Zimbra collaboration suite using the open source code, instead of buying the network edition license so that we can have the following functionalities.

*Full Outlook sync capability for contacts,calendar and tasks using the free open source edition
*Full Mobile sync capability for iphone,blackberry and windows mobile
*Full Zimbra document sharing available in the network edition

Please note: All of the above 3 must be possible by customizing the source code.

Is it possible to edit Zimbra open source code to have the above to properly function.

What type of options do we have here without worrying about the expensive licensing?

I prefer Zimbra over Google apps. However Google apps is kind of taking over slowly with all the messaging collaboration functionality with 25Gigs per user for less than $5 per month.