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].