Richard Stallman began to use the term "free software" to describe software which can be used by anyone for any purpose in 1983 when he launched the free software movement. These freedoms are formally described in The Free Software Definition and include being able to study the source code of a program, adapt it, and to redistribute either the original or a modified copy of the program. He first published a version of this definition in February 1986.[1].
The term "free software" was and is criticized because of the semantic ambiguity of the English word "free." In addition to the freedoms Stallman describes (sometimes termed "libre" or "free as in speech"), it can mean gratis (free as in beer or as in freeware). This ambiguity was also seen as discouraging business adoption [2]. Because of this criticism, "open-source software" was selected during a 1998 strategy session held in Palo Alto attended by Todd Anderson, Larry Augustin, Jon Hall, Sam Ockman, Christine Peterson, and Eric S. Raymond (but not Richard Stallman). The session was arranged in reaction to Netscape's January 1998 announcement of a source code release for Navigator (as Mozilla). Those at the meeting described "open source" as a "replacement label" for free software [3] and founded the Open Source Initiative to promote the term as part of "a marketing program for free software" [4]. Stallman and others object to the term "open-source software" because it does not describe all of the freedoms associated with the free software definition.
Each of the terms "free software" and "open-source software" has both fans and critics. Partly because of the failure to adopt one specific term, other terms have been proposed. These include "Software Libre" (or libre software), "FLOSS" (Free/Libre/Open-Source Software), and "FOSS" (or F/OSS, Free and Open Source Software). These terms share almost identical license criteria and development practices.
"Libre software" was first used publicly in 2000, by the European Commission.[5] The word "libre", borrowed from the Spanish and French languages, means having liberty. This avoids the freedom/cost ambiguity of the word "free".
"FLOSS" was used in 2001 as a project acronym by Rishab Aiyer Ghosh as an acronym for Free/Libre/Open-Source Software. Later that year, the European Commission (EC) used the phrase when they funded a study on the topic.[6]
Unlike "libre software", which aimed to solve the ambiguity problem, "FLOSS" aimed to avoid taking sides in the debate over whether it was better to say "free software" or to say "open-source software".
Proponents of the term point out that parts of the FLOSS acronym can be translated into other European languages, with for example the "F" representing free (English) or frei (German), and the "L" representing libre (Spanish or French), livre (Portuguese), or libero (Italian). However, this term is not often used in official, non-English, documents, since the words in these languages for "free as in freedom" do not have the ambiguity problem of English's "free".
By the end of 2004, the FLOSS acronym had been used in official English documents issued by South Africa [7], Spain[8], and Brazil.[9]
Stallman endorses the term FLOSS to refer to "open source" and "free software" without necessarily choosing between the two camps, however, he asks people to consider supporting the "free software" camp [10].
In February 2002, "F/OSS" appeared on a Usenet newsgroup dedicated to Amiga computer games .[11]. In early 2002, the Department of Defense used the term "FOSS" in what would later be their 2003 report Use of Free and Open Source Software (FOSS) in the U.S. Department of Defense.
Stallman has criticized the term FOSS as Free/Open seems to imply free-of-charge, while Free/Libre makes it clear the reference is to freedom [12].
David A. Wheeler uses the abbreviation "OSS/FS," although it hasn't gained wide adoption[13].
Richard Stallman has suggested that the term "unfettered software" would be an appropriate, non-ambiguous replacement, but that he would not push for it because there was too much momentum, and too much effort, behind the term "free software".
The free software community in India sometimes uses the term "Swatantra software" since the term "Swatantra" means freedom in Sanskrit, which is the ancestor of all Indo-European Languages of India, including Hindi, despite English being the lingua franca.
In The Philippines, "malayang software" is sometimes used. The word "libre" exists in the Filipino language, and it came from the Spanish language, but has acquired the same ambiguity of the English word "free".[14]
None of these terms, or the term "free software" itself, have been trademarked. Bruce Perens of OSI, attempted to register "open source" as a service mark for OSI in the United States of America, but that attempt failed to meet the relevant trademark standards. OSI claims a trademark on "OSI Certified", and applied for trademark registration, but did not complete the paperwork. The United States Patent and Trademark Office labels it as "abandoned".[15]
While the term "free software" is associated with FSF's definition, and the term "open-source software" is associated with OSI's definition, the other terms have not been claimed by any group in particular. This, however, has not led to confusion since the definitions published by FSF and OSI are practically the same.
All of the terms are used interchangeably, the choice of which to use is mostly political (wanting to support a certain group) or practical (thinking that one term is the clearest).
The choice of term has little or no impact on which licenses are valid. The vast majority of software referred to by these terms is distributed under a small set of licenses, all of which are unambiguously accepted by the various de facto and de jure guardians of each of these terms. 50-70% of this software is under the GNU General Public License, and most of the rest is distributed under the terms of the GNU Lesser General Public License, the BSD License, the Mozilla Public License, the MIT Licence, and the Apache License, each with a share of between 2% and 10%.[16]
Free Software Foundation and Open Source Initiative each publish lists of licenses that they accept as complying with their definitions of free software and open-source software respectively.
Apart from these two organizations, the Debian project is seen by some to provide useful advice on whether particular licenses comply with their Debian Free Software Guidelines. Debian doesn't publish a list of "approved" licenses, but its judgments can be tracked by checking what licences are used by software they have allowed into their distribution.[17]
There is also a class of software that is covered by the names discussed in this article, but which doesn't have a license: software for which the source code is in the public domain. The use of such source code, and therefore the executable version, is not restricted by copyright and therefore does not need a free software license to make it free software.