Delphi is the world's biggest auto parts maker. It was divested from General Motors a few years ago. General Motors remains their biggest customer, and owns a large chunk of their stock.
Among their newer products are Quadrasteer (4 wheel steering) featured on the 2003 Chevrolet Silverado, and MagnaRide (magnetic ride stabilization) which will be featured on the 2004 Cadillac XLR.