Section 1.2. Microsoft s Windows Operating System

1.2. Microsoft's Windows^® Operating System

Microsoft Corporation became the dominant software company in the 1980s and 1990s. In 1981, Microsoft released the first version of its DOS operating system for the IBM Personal Computer (DOS is an acronym for "Disk Operating System"). In the mid-1980s, Microsoft developed the Windows operating system, a graphical user interface built on top of DOS. Microsoft released Windows 3.0 in 1990; this new version featured a user-friendly interface and rich functionality. The Windows operating system became incredibly popular after the 1993 release of Windows 3.1, whose successors, Windows 95 and Windows 98, virtually cornered the desktop operating systems market by the late 1990s. These operating systems, which borrowed from many concepts (such as icons, menus and windows) popularized by early Apple Macintosh operating systems, enabled users to navigate multiple applications simultaneously. Microsoft entered the corporate operating systems market with the 1993 release of Windows NT^®. Windows XP, which is based on the Windows NT operating system, was released in 2001 and combines Microsoft's corporate and consumer operating system lines. Windows is by far the world's most widely used operating system.

The biggest competitor to the Windows operating system is Linux. The name Linux derives from Linus, after Linus Torvalds, who developed Linux, and UNIXthe operating system upon which Linux is based; UNIX was developed at Bell Laboratories and was written in the C programming language. Linux is a free, open-source operating system, unlike Windows, which is proprietary (owned and controlled by Microsoft). The source code for Linux is freely available to users, and they can modify it to fit their needs.