The ACOS-4/XVP PX, which is NEC's mainframe OS, considerably enhances
its facilities to establish linkage with UNIX parallel to computers, P
Cs, and other open client/server systems so that the application syste
ms can be easily built and integrated on such systems. The functions a
nd processing provided by a mainframe are classified into seven catego
ries. For each category cooperating functions are provided. These are
seven OLFs (Open Link Facilities).