Atari Program Exchange (APX) was a division of Atari that distributed software for the Atari 8-bit family of home computers through a quarterly mail-order catalog. APX allowed all programmers, not just professionals, to submit their programs for commercial distribution. If selected, that program was added to the catalog along with the credit to that programmer. The brain-child of Dale Yocum, the Atari Program Exchange started in February 1981.