What does APOS stand for?

Adaptive Problem-Oriented Software (SAUS)

Advanced Polar Orbiting Satellite

Advanced Polymer Sys - NASDAQ symbol

Advanced Polymer Systems, Inc. - NASDAQ symbol (NQ)

Airborne Processor Operating System - Aviation (MLEX)

Alberta Professional Outfitters Society - Canada (FOTI)

Apostrophe

Automated Purchase Order System (ALAC)

Cocos Islands - Australia - ICAO location identifier (ICLI)