ALGOL 68S
A subset of ALGOL 68 allowing simpler compilation, intended mainly for numerical computation. It was rewritten in BLISS for the PDP-11, and later in Pascal. It is available as shareware from Charles Lindsey <chl@cs.man.ac.uk>.
Version 2.3 runs on Sun-3 under SunOS 4.x and Atari under GEMDOS (or potentially other computers supported by the Amsterdam Compiler Kit).
["A Sublanguage of ALGOL 68", P.G. Hibbard, SIGPLAN Notices 12(5), May 1977].