APPC
Advanced Program-to-Program Communication; programming interface for peer-level communication between applications over an SNA LU6.2 communications link. APPC is supported in the PWS under DOS (using the APPC/PC product), and under OS/2 Extended Edition Version 1.x and OS/2 Extended Services using the Communications Manager. It is also supported in AS/400 systems and in System/370 hosts running VM/CMS and CICS.