GPM - General Purpose Macro-generator. Early text-processing language
similar to TRAC, implemented on Atlas 2. "A General Purpose
Macrogenerator", C. Strachey, Computer J 8(3):225-241 (Oct 1965).
GPM Programming Language
http://www.programming-languages.co.uk/gpm.html
Large list of computer programming languages arranged alphabetically, with explanations.