The Microsoft Word word processor was first introduced for MS-DOS in 1983. Its design made use of a mouse and WYSIWYG graphics. Its crude WYSIWYG/mouse support was a direct response to the Apple Lisa/Mac, and VisiCorp Visi On. Initially it competed against many popular word processors such as WordStar, Multimate, and WordPerfect. Word for DOS was never really successful.
The Mac version was introduced in 1985 where it acquired a friendlier user interface and gained some popularity. A Microsoft Windows version was introduced in 1989, although Palantir WinText, NBI Legend, and Samna AMI/AMI Pro had beaten them to their own Windows platform. For a time Word for Windows competed with WordPerfect for Windows. There were also ports to OS/2, the Atari ST, and Unix.
The DOS, Mac, and Windows versions are quite different from each other, and each restarted their version numbering at "1.0". Later versions are bundled with Microsoft Office. Also see a complete list of word processors archived on Winworld.
In 1983 Microsoft released the first version of Microsoft Word for DOS on the IBM PC. It is a character cell / text mode based application, but can make use of a Microsoft mouse - which had also just been released. Microsoft Word for DOS was heavily promoted as "WYSIWYG", although its limited on-screen formatting made that a bit of a joke.
It featured an allegedly portable internal code base, and prior to the DOS release was known as "Multi-Tool Word" on Xenix.
Wanted: KF/SCP/TC disk dump of Microsoft Word for DOS 1.00, Microsoft Word for DOS 1.10, early Unix versions.