Aveva Group Plc.(site info)
Supplier of software solutions and services to the process industries, including PDMS for plant design engineering, VANTAGE for engineering change management, and other datacentric design tools.
http://www.aveva.com/
2.
CADArena.com(site info)
Dedicated to users of Cadcentre's PDMS 3D design software. Community forum site that provides support, job listings, and shareware for PDMS users worldwide.
http://www.cadarena.com/