GNU is an operating system which is 100% free software. It was launched in 1983 by Richard Stallman (rms) and has been developed by many people working together for the sake of freedom of all software users to control their computing. Technically, GNU is generally like Unix. But unlike Unix, GNU gives its users freedom.

The GNU system contains all of the official GNU software packages (which are listed below), and also includes non-GNU free software, notably TeX and the X Window System. Also, the GNU system is not a single static set of programs; users and distributors may select different packages according to their needs and desires. The result is still a variant of the GNU system.

GNU is a Unix-like operating system. That means it is a collection of many programs: applications, libraries, developer tools, even games. ... The program in a Unix-like system that allocates machine resources and talks to the hardware is called the “kernel”. GNU is typically used with a kernel called Linux.