Free Software Movement
Social movement launched in 1983 by Richard Stallman with the GNU Project, defining software freedom in terms of four user freedoms and treating proprietary software as an ethical problem. Distinct from the later open-source framing.
The "Free Software Movement" is a social movement founded in 1983 by Richard Stallman with the launch of the GNU Project, and institutionally anchored from 1985 by The Free Software Foundation: Stallman's Organization for Software Freedom. Its central claim is that users of a program are entitled to a specific set of liberties, codified as the "four essential freedoms": the freedom to run the program for any purpose, to study and modify its source code, to redistribute copies, and to distribute modified versions. Software that respects all four is "free software" — free as in freedom, not price. The movement's signature legal innovation is copyleft, expressed in the GNU General Public License (GPL): a license that uses copyright to require derivative works to be distributed under the same free terms, preventing reuse in proprietary products. See Copyleft for the underlying mechanism. The GNU Project's tools (GCC, Emacs, the GNU userland, glibc, coreutils) became the foundation that the Linux kernel later completed into the fully free GNU/Linux operating system. The movement is philosophically distinct from the open-source framing introduced by the Open Source Initiative and popularized through The Cathedral and the Bazaar in 1998. The free software camp treats proprietary software as ethically objectionable — a question of users' rights — while the open-source camp argues for the same licensing in pragmatic, engineering terms. Stallman has described open source as a depoliticized framing that "does not campaign for anything," and the two communities have coexisted uneasily under the umbrella label "FOSS" or "FLOSS" (free/libre and open-source software) ever since.