SP/K (PL/1 Subset) compilers now available for 360/370 and PDP-11
Richard C. Holt, David B. Wortman · ACM SIGMINI Newsletter · 1975
The Computer Systems Research Group of the University of Toronto is now distributing their compilers for SP/k. These compilers support a sequence of subsets of PL/1 called SP/1, SP/2, SP/3, ..., SP/8 that have been designed for teaching programming. Generally., programs that run without errors under the SP/k compilers will run with the same results under other PL/1 compilers such as IBM's PL/1 F compiler, IBM's check-out compiler or Cornell University's PL/C compiler. (See the references for specifications of SP/k and discussion of using PL/1 for teaching.)