Microsoft are the largest computer software company in the World. They manufacture operating systems, computer games, office application software, hardware such as keyboards, joysticks and mice and much more. Microsoft was started by Paul Allen and Bill Gates in 1975, and has since developed MS-DOS and the Windows operating systems. They are currently based in Seattle USA. The' Microsoft' name was first used on 11/29/75 in a letter to Paul Allen from Bill Gates. In the letter Bill uses the name "Micro-soft" to refer to their Partnership. The trade name "Microsoft" was then registered with the Office of the Secretary of the State of New Mexico in November 1976. Microsoft made it's named by developing the BASIC, FORTRAN and COBOL PC programming languages. The first language they developed was BASIC, this was followed by FORTRAN in 1977 and COBOL-80 in 1978. BASIC and FORTRAN were also released on the Atari, Cromemco, and Texas Instruments computer systems. Along with developing the MS-DOS operating system in the early 1980's Microsoft also developed the XENIX operating system (a UNIX derivative). It was at the same time that Microsoft first developed it's spreadsheet and office applications (in 1987 Microsoft announces Microsoft Excel for Window). In 1988 Microsoft and IBM announced the delivery of the jointly developed Operating System/2 (OS/2). It was at this point that Microsoft became the top software vendor, and has never looks backed.