Although they are based on the same layering technology, Unidesk version 2 and 3 are very different from Citrix App Layering (formerly Unidesk version 4). This document lays out the major product differences for exiting version 2 and 3 customers to help them understand those differences and plan for how to migrate to App Layering.  It also contains a basic walkthrough for installing App Layering and publishing your first image.

Refer to the Transitioning to Citrix App Layering section of Citrix Documentation - Unidesk.