The Free Software Foundation (FSF) is a 501 (c)(3) non-profit organization founded by Richard Stallman on October 4, 1985. The organization supports the free software movement, with its preference for software being distributed under copyleft ("share alike") terms, such as with its own GNU General Public License. The FSF was incorporated in Boston where it is also based.
From its founding until the mid-1990s, FSF's funds were mostly used to employ software developers to write free software for the GNU Project and its employees and volunteers have mostly worked on legal and structural issues for the free software movement and the free software community.