Unix-like computer operating system assembled under the model of free and open source software development and distribution.
Operating system produced by Microsoft as an add-on to MS-DOS in response to the growing interest in graphical user interfaces.
Apple's mobile operating system, based on the concept of direct manipulation, using multi-touch gestures.
Free BSD Family
Free complete Unix-like operating system that holds kernel, device drivers, and all of the userland utilities in the same source code revision tracking tree.
Operating system for mobile devices such as smartphones and tablet computers, consists of a kernel based on the Linux kernel.
Virtual machine software suite, which allows to set up multiple virtual machines and use one or more simultaneously with the hosting operating system.