From V.E.R.A. -- Virtual Entity of Relevant Acronyms (February 2016) :
MAS
Multi Agent Systems (AI)
From The Free On-line Dictionary of Computing (30 December 2018) :
MAS
Modula-2 Algebra System. Runs on IBM PC, Atari, Amiga.
ftp://alice.fmi.uni-passau.de)">(ftp://alice.fmi.uni-passau.de).
["Modula-2 Algebra System", H. Kredel, Proc DISCO 90 Capri,
LNCS 429, Springer 1990, pp270-271].