- In 1991, MS-DOS was the standard operating system of the home and business computer. A bare-bones operating system, MS-DOS was distributed by Microsoft and faced little competition from Apple, whose Macintosh computers were expensive compared to PCs. UNIX was too expensive for software developers to license and its source code was not freely available for students of computer science to study. Students who wanted to learn about operating systems could learn by studying MINIX, an operating system created by Andrew Tanenbaum in C and Assembly.
- Linux was created by Linus Torvalds, a Finnish student of Computer Science at the University of Helsinki who wanted to create an operating system more powerful than MINIX, which was regarded as a student's operating system. The first version, Linux 0.01, was released in September, 1991, and was considered a "hobby" by its creator. Torvalds's project was met with enthusiasm by the community and other developers began working on the system to help improve the code.
- As Linux grew in popularity among programmers and developers, Torvalds licensed the source code under the GNU GPL, which ensured that the code would be free to copy, study, and modify -- as long as any changes were also made freely available. Since Linux itself was free, companies like Red Hat sold distributions of the operating system that came pre-packaged with utility software and applications while enthusiasts built their own versions of the operating system. Because of the relative difficulty of use and general incompatibility with the vastly more popular Microsoft Windows, however, Linux remained an operating system for programmers.
- In 2004, Ubuntu Linux -- an offshoot of the Debian Project -- was released by Canonical Ltd. New versions of Ubuntu appeared every six months and the operating system received numerous awards for ease of use and stability. Ubuntu helped popularize Linux by allowing home users to try Linux by running the operating system from the CD without installing Linux to the computer. By 2007, it was the most popular Linux distribution available; it quickly became the third most popular desktop operating system in the world after Microsoft's Windows and Apple's Mac OS X.