Versions for MS-DOS include the following:
- 1983 November — Word 1
- 1985 — Word 2
- 1986 — Word 3
- 1987 — Word 4 aka Microsoft Word 4.0 for the PC
- 1989 — Word 5
- 1991 — Word 5.1
- 1991 — Word 5.5
- 1993 — Word 6.0
Versions for the Macintosh (Mac OS and Mac OS X) include the following:
- 1985 January — Word 1 for the Macintosh
- 1987 — Word 3
- 1989 — Word 4
- 1991 — Word 5
- 1993 — Word 6
- 1998 — Word 98
- 2000 — Word 2001, the last version compatible with Mac OS 9
- 2001 — Word v.X, the first version for Mac OS X only
- 2004 — Word 2004, part of Office 2004 for Mac
- 2008 — Word 2008, part of Office 2008 for Mac
Versions for Microsoft Windows include the following:
- 1989 November — Word for Windows 1.0 for Windows 2.x, code-named Opus
- 1990 March — Word for Windows 1.1 for Windows 3.0, code-named Bill the Cat
- 1990 June — Word for Windows 1.1a for Windows 3.1
- 1991 — Word for Windows 2.0, code-named Spaceman Spiff
- 1993 — Word for Windows 6.0, code-named T3 (renumbered 6 to bring Windows version numbering in line with that of DOS version, Macintosh version and also WordPerfect, the main competing word processor at the time; also a 32-bit version for Windows NT only)
- 1995 — Word 95 (version 7.0) - included in Office 95
- 1997 — Word 97 (version 8.0) included in Office 97
- 1998 — Word 98 (version 8.5) only included in Office 97 Powered By Word 98—only released in Japan and Korea
- 1999 — Word 2000 (version 9.0) included in Office 2000
- 2001 — Word 2002 (version 10) included in Office XP
- 2003 — Word 2003 (officially "Microsoft Office Word 2003") - (ver. 11) included in Office 2003
- 2006 — Word 2007 (officially "Microsoft Office Word 2007") - (ver. 12) included in Office 2007; released to businesses on November 30th 2006, released worldwide to consumers on January 30th 2007
Versions for SCO UNIX include the following:
Versions for OS/2 include the following:
- 1992 — Microsoft Word for OS/2 version 1.1B
