When Mathematica came out (1988) there were already Lisps for PCs and Macs. Lisp at that time made the switch to Common Lisp. Symbolics Lisp Machines were used

When Mathematica came out (1988) there were already Lisps for PCs and Macs. Lisp at that time made the switch to Common Lisp. Symbolics Lisp Machines were used for higher-end AI, CAD, etc. domains. There was a bunch of very different options across many platforms (PCs, Macs, UNIX Workstations, ...). Macsyma itself ran on various platforms, incl. Lisp Machines, UNIX, VAX/VMS, and then also on Windows. Derive even ran on some TI calculators. It was written in muLISP.