Free software
Free software
Free software is software that respects users' freedom and community. It is defined by the four essential freedoms: the freedom to run the program for any purpose, to study and change the source code, to redistribute copies, and to distribute modified versions. The concept was formally articulated by Richard Stallman in the 1980s through the GNU Project and the Free Software Foundation (FSF). Free software is distinct from open source software, though the two movements share many practical goals; the free software movement emphasizes ethical and social issues, while the open source movement focuses on technical and business advantages.
The term "free" refers to liberty, not price. Free software may be distributed commercially or gratis, but its license must guarantee the listed freedoms. Common free software licenses include the GNU General Public License (GPL), the MIT License, and the Apache License.
History
The free software movement began in 1983 when Richard Stallman announced the GNU Project, aiming to create a complete Unix-like operating system that was freely modifiable and redistributable. In 1985, he founded the FSF to promote and protect free software legally and philosophically. The GNU General Public License, first released in 1989, introduced the concept of copyleft – using copyright law to ensure freedom remains attached to the software.
In the 1990s, the Linux kernel (started by Linus Torvalds) combined with GNU utilities to form a fully functional free operating system (often called GNU/Linux). The growth of the internet and the release of the Netscape browser source code in 1998 spurred the open source label, causing a schism between the ethical free software movement and the pragmatic open source movement. Despite these differences, free software now underpins much of the internet, including servers, embedded systems, and mobile devices (via Android's kernel).
Key principles
- Freedom to run the program for any purpose.
- Freedom to study the source code and adapt it.
- Freedom to redistribute copies freely.
- Freedom to improve the program and release improvements.
These principles are enshrined in the Free Software Definition published by the FSF. Software that does not meet these criteria is considered proprietary or non-free.