The GNU Project is a free software, mass collaboration project, announced in 1983 by Richard Stallman. It initiated the GNU operating system, software development for which began in January 1984. GNU is a recursive acronym that stands for "GNU's Not Unix".

The founding goal of the project was, in the words of its initial announcement, to develop "a sufficient body of free software [...] to get along without any software that is not free." To make this happen, the GNU Project began working on an operating system called GNU. With the Linux kernel being released under the GNU General Public License in 1992, the GNU project no longer relied on any proprietary software to run.

Current work of the GNU Project includes software development, awareness building, and political campaigning.