VDI for compatibility

Real Desktop Operating Systems

Virtual Machines run Windows XP or Windows Vista just like they do on physical hardware so applications work normally and without modification.

No second multi user desktop need be designed, tested and maintained and skills such as those for Terminal Services are not needed.

Applications can make system level changes such as registry writes and DLL replacements where necessary.
Existing corporate desktop configurations can be easily imported.

Isolation

Each Virtual Machine runs separately, so a crashed VM or a poorly behaving application does not affect other users on the same server.

VDI is suitable for developers because any type of change can be made to a VM without affecting other users.