Posted to Bitbucket and under the GPL2 license. From their presser:
It was in September, 1997 - over 19 years ago (we'll round that out to 20, for marketing reasons) - when us humble folk from Running With Scissors unleashed our Robotron-inspired isometric shooter POSTAL to the unsuspecting public at large. It was an instant hit, grabbing the attention of gamers, parents and politicians across the country, and we've been supporting and updating it ever since. But now, (almost) 20 years later, we are entrusting our fans with the future of our game, by releasing its source code to the public.
https://bitbucket.org/gopostal/postal-1-open-source
