Microsoft Corporation is a major American technology company based in Redmond, Washington. It played a central role in the spread of personal computers through its Windows operating system and has grown into a broad technology firm with major businesses in cloud computing, internet services, artificial intelligence, and video games. Microsoft ranks as the world’s largest software company by revenue and is consistently among the most valuable public companies and global brands.
Origins and early growth
Bill Gates and Paul Allen founded the company in 1975 to sell BASIC interpreters for the Altair 8800 microcomputer. In the mid-1980s Microsoft established dominance in the PC operating-system market first with MS-DOS and then with Windows. Its 1986 initial public offering and the rapid rise in its stock price made Gates, Allen, and many early employees wealthy; the IPO is credited with creating three billionaires and roughly 12,000 millionaires among Microsoft staff. From the 1990s onward the company steadily broadened its product lines beyond operating systems.
MS-DOS (Microsoft Disk Operating System) was the product that first propelled Microsoft to industry leadership. In 1980, as IBM prepared to launch its first personal computer, it needed an operating system. Microsoft licensed (and later acquired the full rights to) 86-DOS, a CP/M-compatible system originally written by Tim Paterson at Seattle Computer Products. Microsoft adapted it for the IBM PC’s Intel 8088 processor and released it in 1981 as PC DOS for IBM machines and as MS-DOS for the growing market of IBM-compatible “clone” computers.
MS-DOS was a single-tasking, command-line operating system. Users interacted with it by typing text commands at a prompt (for example, DIR to list files, COPY to duplicate them, or FORMAT to prepare disks). It used the FAT (File Allocation Table) file system, supported batch files for simple automation, and managed floppy-disk and later hard-disk storage. Early versions were quite limited in memory handling; later releases (especially MS-DOS 5.0 and 6.x in the early 1990s) added improved memory management, disk-compression utilities, and better support for larger hard drives.
Throughout the 1980s MS-DOS became the de-facto standard operating system for the vast majority of personal computers. Its open licensing model allowed dozens of manufacturers to ship it with their hardware, rapidly expanding the IBM-compatible PC platform. Microsoft’s ability to sell the same operating system to both IBM and its competitors was a key factor in the company’s explosive growth. Windows began life in 1985 as a graphical shell that ran on top of MS-DOS; full independence from DOS only arrived with Windows 95 and later NT-based versions. The final standalone release, MS-DOS 6.22, appeared in 1994. Although the pure command-line DOS environment largely disappeared from consumer use, its design principles and file-system conventions influenced PC computing for decades.
Leadership transitions
Steve Ballmer succeeded Gates as CEO in 2000. During his tenure Microsoft made its then-largest acquisition (Skype in 2011), launched its first self-designed PC line (Surface in 2012), and created Microsoft Mobile through the purchase of Nokia’s phone business. Satya Nadella became CEO in 2014 and shifted the company’s strategic emphasis toward cloud computing. Under his leadership Microsoft acquired LinkedIn in 2016, expanded its gaming operations (forming the Microsoft Gaming division in 2022 and completing the acquisition of Activision Blizzard in 2023), and continued to grow its cloud and AI offerings.
Core products and services
Since the 1990s Microsoft has held leading positions in PC operating systems and office productivity software. Its best-known products include the Windows operating-system family and the Microsoft Office / Microsoft 365 suite (notably Word, Excel, and PowerPoint). Hardware offerings center on the Surface line of computers and the Xbox family of gaming consoles and online services. Online consumer services include the Bing search engine, the MSN portal, Outlook.com email, and the Microsoft Store. In the enterprise and developer space the company provides the Azure cloud platform, Microsoft SQL Server, and Visual Studio.
Valuation and criticisms
In April 2019 Microsoft became the third U.S. publicly traded company to reach a market capitalization above $1 trillion. The company has long faced criticism for alleged monopolistic behavior. Its software has also been faulted for issues of usability, reliability, and security.
