"By 1978, there existed over 80 distinct Pascal implementations on hosts ranging from the Intel 8080 microprocessor to the Cray-1 supercomputer. But Pascal’s usefulness was not restricted to educational institutions; by 1980 all four major manufacturers of workstations (Three Rivers, HP, Apollo, Tektronix) were using Pascal for system programming. Besides being the major agent for the spread of Pascal implementations, the P-system was significant in demonstrating how comprehensible, portable, and reliable a compiler and system program could be made. Many programmers learned much from the P-system, including implementors who did not base their work on the P-system, and others who had never before been able to study a compiler in detail. The fact that a compiler was available in source form caused the P-system to become an influential vehicle of extracurricular education." (Niklaus Wirth)

http://pascal.hansotten.com/niklaus-wirth/recollections-abou...