Microsoft Word is developed by Microsoft. It was first released on October 25, 1983,[6] under the name Multi-Tool Word for Xenix systems.[7][8][9] Subsequent versions were later written for several other platforms including IBM PCs running DOS (1983), Apple Macintosh running the Classic Mac OS (1985), AT&T UNIX PC (1985), Atari ST (1988), OS/2 (1989), Microsoft Windows (1989), SCO Unix (1994), and macOS (2001).

Commercial versions of Word are licensed as a standalone product or as a component of Microsoft Office 365, or Microsoft 365 Premium subscription, Windows RT or the discontinued Microsoft Works suite.