Linux is the best-known and most-used open source operating system. An operating system kernel first released on September 17, 1991, by Linus Torvalds. The Linux or Linux OS is a freely distributable, cross-platform operating system based on Unix that can be installed on PCs, laptops, netbooks, mobile and tablet devices, video game consoles, servers, supercomputers and more. The most current version of Windows for end users is Windows 10 released in 2015. Since its release, there have been over a dozen versions of Windows. The first version of Windows 1.0, released in 1985, was simply a GUI offered as an extension of Microsoft’s existing disk operating system, or MS-DOS. Gates and Allen co-developed Xenix (a version of Unix) and also collaborated on a BASIC interpreter for the Altair 8800.
Microsoft got its start with the partnership of Bill Gates and Paul Allen in 1975. Microsoft chose the keyword 'Windows' because of the multiple windows that allow different tasks and programs to be run at the same time. Approximately 90 percent of PCs run some version of Windows. Featuring the first graphical user interface (GUI) for IBM-compatible PCs, and dominate the PC market. Windows operating system (OS) developed by Microsoft Corporation to run personal computers (PCs).