Pastel is an extended version of the Pascal programming language, created in c. 1982 for Amber, an operating system for the S-1 supercomputer project at Lawrence Livermore National Laboratory in California .[1] The Pastel compiler was the inspiration for Richard Stallman's GNU C compiler.[2] Pastel was conceived by Jeffrey M. Broughton, then Project Engineer in charge of compilers and operating system software for the S-1 project,[3] because of dissatisfaction with the PL/1 language in which Amber was being implemented. The language was named Pastel ("an off-color Pascal").
Compared with Pascal compilers of that period, Pastel's features included:[4]