VDM are the initials of Vincent de Moor, a highly successful trance artist. The name VDM is technically one of his many guises.
The producer from The Hague, The Netherlands, is part of the first generation of dutch tranceproducers that scores outside of the Netherlands. Together with Ferry Corsten (System F) and Tiesto, he is responsible for the main breakthrough of trance music in the late 90's. Vincent is mainly very succesfull in the UK.