Techopedia explains Free Software Foundation (FSF)
The Free Software Foundation was established to encourage the development of free software. The free software movement, which liberated users to freely create and share their software and programs, was a major driver behind this foundation. FSF's primary objective is to instigate the rejection of propriety software that cannot be shared, published or altered legally.
FSF also maintains a team of in-house software programmers that develop software and applications that can be revised and distributed by end users, and are available under the GNU General Public License (GPL).