Atari Program Exchange (APX) was a division of Atari, Inc. that sold software via mail-order for Atari 8-bit computers from 1981 until 1984. Quarterly APX catalogs were sent to all registered Atari 8-bit owners. APX encouraged any programmer, not just professionals, to submit video games, educational software, applications, and utilities. A few internally developed Atari products were sold through APX, such as Atari Pascal, the developer handbook De Re Atari, and a port of the arcade video game Kangaroo.
If accepted, a submitted program was added to the catalog with credit given to the programmer. The top submissions of the quarter in each category were recognized. One program each year received the top honor: the Atari Star award. APX releases Eastern Front (1941), Caverns of Mars, and Atari Star winner Typo Attack, were moved to Atari's official product line.
The brainchild of Dale Yocum, the Atari Program Exchange started in February 1981. In 1982 its management was taken over by Fred Thorlin, who operated it until it closed. APX published quarterly catalogs until 1984, when new Atari CEO James J. Morgan closed down the mail-order division. Some APX software was later picked up by Antic Software and branded as "APX Classics".