<P> The first operating system publicly released by the company was a variant of Unix announced on August 25, 1980 . Acquired from AT&T through a distribution license, Microsoft dubbed it Xenix, and hired Santa Cruz Operation in order to port / adapt the operating system to several platforms . This Unix variant would become home to the first version of Microsoft's word processor, Microsoft Word . Originally titled "Multi-Tool Word", Microsoft Word became notable for its use of "What You See Is What You Get", or WYSIWYG pioneered by the Xerox Alto and the Bravo text editor in the 1970s . </P> <P> Word was first released in the spring of 1983, and free demonstration copies of the application were bundled with the November 1983 issue of PC World, making it the first program to be distributed on - disk with a magazine . However, Xenix was never sold to end users directly although it was licensed to many software OEMs for resale . It grew to become the most popular version of Unix, measured by the number of machines running it (note that Unix is a multi-user operating system, allowing simultaneous access to a machine by several users). By the mid-1980s Microsoft had gotten out of the Unix business, except for an interest in SCO . </P> <P> DOS (Disk Operating System) was the operating system that brought the company its real success . IBM first approached Microsoft about its upcoming IBM Personal Computer (IBM PC) in July 1980 . On August 12, 1981, after negotiations with Digital Research failed, IBM awarded a contract to Microsoft to provide a version of the CP / M operating system, which was set to be used in the IBM PC . For this deal, Microsoft purchased a CP / M clone called 86 - DOS from Tim Paterson of Seattle Computer Products for less than US $100,000, which IBM renamed to IBM PC DOS . Microsoft did not have an operating system when they closed the deal with IBM and IBM had not done their homework . Due to potential copyright infringement problems with CP / M, IBM marketed both CP / M and PC DOS for US $240 and US $40, respectively, with PC DOS eventually becoming the standard because of its lower price . 35 of the company's 100 employees worked on the IBM project for more than a year . When the IBM PC debuted, Microsoft was the only company that offered operating system, programming language, and application software for the new computer . </P> <P> InfoWorld stated in 1984 that Microsoft, with $55 million in 1983 sales, </P>

Who did microsoft strike a deal with to provide dos operating system