> With SABRE up and running, IBM offered its expertise to other airlines, and soon developed Deltamatic for Delta Air Lines on the IBM 7074, and PANAMAC for Pan American World Airways using an IBM 7080. In 1968, they generalized their work into the PARS (Programmed Airline Reservation System), which ran on any member of the IBM System/360 family and thus could support any sized airline. The operating system component of PARS evolved into ACP (Airlines Control Program), and later to TPF (Transaction Processing Facility). Application programs were originally written in assembly language, later in SabreTalk, a proprietary dialect of PL/I, and now in C and C++.

https://en.wikipedia.org/wiki/Sabre_(computer_system)