Source : Free On-Line Dictionary of Computing

FORMAC
     
        FORmula MAnipulation Compiler.  J. Sammet & Tobey, IBM Boston
        APD, 1962.  An extension of {Fortran} for {symbolic
        mathematics}.  Versions: PL/I-FORMAC and FORMAC73.
     
        ["Introduction to FORMAC", J.E. Sammet et al, IEEE Trans Elec
        Comp (Aug 1964)].
     
        [Sammet 1969, pp. 474-491].