Short for Advanced Program-to-Program Communications. Also known as LU 6.2 and based on IBM's SNA, APPC is a communication protocol that transaction programs in a distributed computing environment can use to talk to each other. Using APPC, interconnected systems can communicate and share the processing of programs. It consists of two interfaces: programming and data-exchange. The programming interface replies to requests from programs requiring communication; the data-exchange interface establishes sessions between programs.
APPC is an open standard and is supported on most platforms.