NPC is the NATO Programming Centre. It is responsible for system support and maintenance of NATO's Air Command and Control Systems. Amongst these systems is also the NATO Air Command and Control System ACCS.
The centre is located in Glons, a village close to the cities of Tongeren and Liège, Belgium. It employs nearly 200 people. It works closely with the NATO ACCS Management Agency NACMA for the ACCS Programme and with NATO Maintenance and Support Agency NAMSA for the maintenance of various Air C2 buffer systems.
web page of NPC at http://www.npc.nato.int/
NATO structure on http://www.nato.int/structur/structure.htm
Armed Forces UK on http://www.armedforces.co.uk/mod/listings/l0009.html