Microsoft Multiplan (.mp)

MP is the native format used by Multiplan, a spreadsheet program developed by Microsoft and introduced in 1982 as a competitor to VisiCalc. Initially released for computers running CP/M, it was developed using a Microsoft proprietary p-code C compiler to facilitate portability to systems such as MS-DOS, Xenix, Commodore 64 and 128, TI-99/4A, Radio Shack TRS-80 Model II and 4, TRS-80 Model 100, Apple II, AT&T UNIX PC, and Burroughs B20 series.

Despite the release of Microsoft Chart as a graphics companion program, Multiplan continued to be outsold by Lotus 1-2-3. It was eventually replaced by Microsoft Excel on both the Apple Macintosh (1985) and Microsoft Windows (1987). Although over a million copies were sold, Multiplan was unable to effectively challenge Lotus 1-2-3. According to Bill Gates, this was due to the excessive number of ports.