A movement in software away from restrictions on use. Free, in this case, means freedom but doesn't mean without cost.
GNU/Linux operating system is an example of Free Software; companies sell CD containing GNU/Linux and other Free Software, and sell services based on support or customisation of the software.
Software is Free Software, if it comes with these four freedoms:
- To run the program, for any purpose.
- To modify the program to suit your needs. (To make this freedom effective in practice, you must have access to the source code, since making changes in a program without having the source code is exceedingly difficult.)
- To redistribute copies, either gratis or for a fee.
- To distribute modified versions of the program, so that the community can benefit from your improvements.
These freedoms are given to users in the form of a copyright license. The most commonly used Free Software license is the GNU General Public License (GPL), but there are many others. To make it easier for people to distinguish between Free and non-Free software, FSF maintain a license list which categorises licenses and provides a description of the benefits or problems with each license.
Although these requirements seem specific and possibly available to interpretation, as the computer industry gradually embraces Open Source, the appearance of a variety of different licenses restricting specific behavior has resulted in a great deal of confusion and frustration. Many license activities contrary to the original spirit of collaboration have hampered development and made many wonder if Open Source is really a useful tool. Software that breaks follows the criteria stated above, according to the Free Software Foundation is described as either "free" or "non-free."
Below is a short list of some Free and non-Free licenses.
- Microsoft Shared Source License
- Apple Public Shared License. 1.x is non-free, 2.0 is free software and incompatible with the GPL. (was changed in Jan 2003 to the FSF's approval).
All licenses have their own issues. The GPL is sometimes accused of behaving like a virus, forcing the developer to release source code on modifications they release in binary format (either for free or for money). Meanwhile, the BSD once required users to list an advertisement for Berkley software (this has since been rescinded).
The GPL is still very popular because it encourages individual hackers to contribute, encouraging further innovation in the way scientific research is exposed to the scientific community, even though the research can often still make companies money. The knowledge that one's work will continue after them is a karmic benefit as well. The BSD License, meanwhile, has no such requirement and is seen by GPL users as exploitable by companies who do not give back to the community that provided the original code.
Occasionally, companies will license different parts of a software release differently, as in the case with Ogg Vorbis. Vorbis released the codecs under the "business-friendly" BSD License while releasing the player under the GPL to encourage development.
The Free Software movement began in 1983 when Richard Stallman announced the GNU Project. Before starting the GNU project, Stallman worked in the Massachusetts Institute of Technology A.I. lab, where it was normal for people to share software and source code. In the early eighties, this software sharing community was destroyed when a new company hired away the most of the lab staff. The GNU project was Stallmans way of rebuilding his lost community, but this time on a global scale.
In 1985, he founded the Free Software Foundation (FSF), a non-profit organization created to support the GNU project and provide infrastructure for the growing Free Software community.
The ambiguity of the english word "free" has lead to some confusion. Explantions of Free Software to people unfamiliar with the concept usually include the phrase "think free-speech, not free beer". English is the only known language to have this ambiguity, so Free Software advocates in non-english speaking countries are encouraged to use the local (unambiguous) translation. A list of translations is available on the FSF website.
The multilingual term "Libre Software" is often used in countries that speak some French or Spanish. The term "unfettered software" was briefly considered by Stallman, but after twenty years it would be very troublesome to change the term and the ambiguity of the term often provides a good opertunity to explain the concept more thoroughly. Alternative names such as "Freed Software" and "Liberated Software" have been deemed unusable because they imply that the software was previously non-Free, which is not the case for most Free Software.
- The GNU Project Free Software Definition
- Libresociety.org Theories of Free Software and the Commons
- FLOSS - Free/Libre and Open Source Software (FLOSS): Survey and Study. Here is a full report.
- Why FLOSS? Look at the Numbers! A (mostly) quantitative study from David A. Wheeler.
- Activist Research and the Transformation of Daily Life: Free Software Movement