What is the operating system used with XXX?
Multiplan
Multiplan was released first for computers running CP/M; it was developed using a Microsoft proprietary p-code C compiler as part of a portability strategy that facilitated ports to systems such as MS-DOS, Xenix, Commodore 64 and 128, Texas Instruments TI-99/4A, Radio Shack TRS-80 Model II, TRS-80 Model 4, TRS-80 Model 100 (on ROM), Apple II, and Burroughs B-20 series.
CP/M MS-DOS Xenix