ABS stands for Anti-skid Braking System, and it comes in most newer cars (my little 1999 Japanese Echo has it). It enables you to continue to steer normally through a skid, and can reduce your stopping time. It applies the brakes in a series of rapid bursts, rather than just locking them up. It might not have been much help in your situation, though it's possible it might have stopped you a few inches faster. You might well have it. Did your brakes make a sort of a pneumatic drill hammering when you applied them? If so, that was the ABS kicking in.