Free software is software that grants its users four essential freedoms, as articulated by Richard Stallman and the Free Software Foundation: the freedom to run the program for any purpose (freedom 0), to study how it works and change it (freedom 1), to redistribute copies (freedom 2), and to distribute modified versions (freedom 3). "Free" here refers to liberty, not price—"free as in free speech, not as in free beer."
The free software movement began in 1983 when Stallman launched the GNU project in response to the increasing enclosure of software behind restrictive licences and non-disclosure agreements. He argued that users have a fundamental right to control the software running on their computers, and that proprietary software undermines community by forbidding sharing. The GNU General Public License, drafted by Stallman with legal assistance, was designed to enforce these freedoms by requiring that derivative works remain free.
Free software and open source describe largely the same body of code but from different moral standpoints. Free software frames the issue as one of user rights and ethics; open source emphasises practical advantages and business compatibility. Linux distributions that adhere strictly to the Free Software Foundation's guidelines (such as Trisquel or GNU Guix System) exclude any non-free firmware or drivers; most mainstream distributions pragmatically include them.
Related terms: GNU, GPL, Open Source
Discussed in:
- Chapter 2: A History of Unix and Linux — GNU: The Free Software Vision
Also defined in: Textbook of Linux