I am in the process of designing some major projects for my company, which unfortunately has a long history of mergers and accusations resulting in no single directory for users. While there are plans in the works to get everyone in a directory (AD or OpenLDAP), it will take longer to do this than it will for us to implement Zimbra.
Since our Zimbra install will eventually service all 10K+ employees I would like to leverage it as a authentication source for other projects like Knowledge Tree and Openfire.
If you are, are you managing the directory from Zimbra or are you using other tools?
What issues have you found?