Microsoft is a United States-based company that develops and sells a wide variety of software products and services for business and personal computing. Microsoft is the world's largest supplier of operating systems (OSs) and other software for IBM-compatible personal computers. The Microsoft Windows OS is the most widely used OS in the world. Microsoft operates subsidiary and sales offices in more than 50 countries and employs nearly 44,000 people worldwide, but performs nearly all of its research and development at its corporate headquarters in Redmond, Washington.

Microsoft's best-known products include Microsoft Disk Operating System (MS-DOS), Microsoft Windows, and Windows NT. Its popular programs Word (a word processor), Excel (a spreadsheet), PowerPoint (for business presentations), and Access (for databases) are sold individually and also bundled together as Microsoft Office (a suite of integrated office software). The company also makes such software programs as BackOffice (an integrated set of server products), Microsoft...