# Free Software
Free Software is software that respects users' freedom and community, as defined by [[Richard Stallman]] and the [[Free Software Foundation (FSF)]]. "Free" refers to freedom (libre), not price—summarized as "free as in speech, not free as in beer." The movement began in 1983 when Stallman launched the [[GNU is not Unix (GNU)|GNU]] project to create a complete free operating system.
The free software philosophy treats software freedom as an ethical imperative, not merely a practical development methodology. Stallman argues that proprietary software is fundamentally unjust because it gives developers power over users. This distinguishes free software from [[Open Source]], which emphasizes practical benefits (code quality, collaboration) rather than ethical principles.
## The Four Freedoms
Free software is defined by four essential freedoms:
| Freedom | Description |
|---------|-------------|
| Freedom 0 | Run the program for any purpose |
| Freedom 1 | Study how the program works and modify it (requires source code) |
| Freedom 2 | Redistribute copies to help others |
| Freedom 3 | Distribute copies of your modified versions |
Software that provides all four freedoms is "free software." Missing any one means the software is proprietary.
## Free Software vs Open Source
| Aspect | Free Software | [[Open Source]] |
|--------|---------------|-----------------|
| Philosophy | Ethical imperative | Practical benefits |
| Focus | User freedom | Development methodology |
| Origin | Stallman, FSF (1983) | OSI (1998) |
| Terminology | "Free as in freedom" | Business-friendly |
| Goal | Social justice | Better software |
Both movements often overlap in practice—most free software is also open source and vice versa. The [[Free and Open Source Software (FOSS)]] umbrella term bridges both.
## "Free" Ambiguity
English's single word "free" causes confusion:
- **Libre** (freedom): The intended meaning
- **Gratis** (no cost): Not the primary concern
Free software can be sold; what matters is that users have the four freedoms. Conversely, gratis software (freeware) without source code is not free software.
## Free Software Licenses
Licenses that guarantee the four freedoms:
- [[GNU General Public License (GPL)]] (copyleft)
- [[LGPL License]] (weak copyleft)
- [[Affero General Public License (AGPL)]] (network copyleft)
- [[MIT License]], [[BSD License]] (permissive)
- [[Apache 2.0 License]] (permissive with patents)
## Key Organizations
- **[[Free Software Foundation (FSF)]]**: Stallman's organization, stewards GNU and GPL
- **Software Freedom Conservancy**: Fiscal sponsor for free software projects
- **Electronic Frontier Foundation (EFF)**: Digital rights advocacy
## References
- https://www.gnu.org/philosophy/free-sw.html (official definition)
- https://www.fsf.org
- https://en.wikipedia.org/wiki/Free_software
## Related
- [[Richard Stallman]]
- [[Free Software Foundation (FSF)]]
- [[GNU is not Unix (GNU)]]
- [[Open Source]]
- [[Free and Open Source Software (FOSS)]]
- [[GNU General Public License (GPL)]]
- [[Open Source Initiative (OSI)]]