Free software or libre software is computer software distributed under terms that allow users to run the software for any purpose as well as to study, change, and distribute it and any adapted versions. Free software is a matter of liberty, not price: users—individually or in cooperation with computer programmers—are free to do what they want with their copies of a free software regardless of how much is paid to obtain the program. Computer programs are deemed free insofar as they give users ultimate control over the first, thereby allowing them to control what their devices are programmed to do.
An open-source license is a type of license for computer software and other products that allows the source code, blueprint or design to be used, modified and/or shared under defined terms and conditions. This allows end users and commercial companies to review and modify the source code, blueprint or design for their own customization, curiosity or troubleshooting needs. Open-source licensed software is mostly available free of charge, though this does not necessarily have to be the case. Licenses which only permit non-commercial redistribution or modification of the source code for personal use only are generally not considered as open-source licenses. However, open-source licenses may have some restrictions, particularly regarding the expression of respect to the origin of software, such as a requirement to preserve the name of the authors and a copyright statement within the code, or a requirement to redistribute the licensed software only under the same license. One popular set of open-source software licenses are those approved by the Open Source Initiative (OSI) based on their Open Source Definition (OSD).
Gecko is a browser engine developed by Mozilla. It is used in the Firefox browser, the Thunderbird email client, and many other projects.
The Apache License is a permissive free software license written by the Apache Software Foundation (ASF). The Apache License, Version 2.0 requires preservation of the copyright notice and disclaimer. Like other free software licenses, the license allows the user of the software the freedom to use the software for any purpose, to distribute it, to modify it, and to distribute modified versions of the software, under the terms of the license, without concern for royalties. This makes the Apache License a FRAND-RF license. The ASF and its projects release the software they produce under the Apache License. The license is also used by many non-ASF projects.
Open-source software (OSS) is a type of computer software in which source code is released under a license in which the copyright holder grants users the rights to study, change, and distribute the software to anyone and for any purpose. Open-source software may be developed in a collaborative public manner. Open-source software is a prominent example of open collaboration.
The Netscape Public License (NPL) is a free software license, the license under which Netscape Communications Corporation originally released Mozilla.
In computing, the Common Public License (CPL) is a free software / open-source software license published by IBM. The Free Software Foundation and Open Source Initiative have approved the license terms of the CPL.
The Sun Industry Standards Source License (SISSL) is now a retired free and open source license, recognized as such by the Free Software Foundation and the Open Source Initiative (OSI). Under SISSL, developers could modify and distribute source code and derived binaries freely. Furthermore, developers could choose to keep their modifications private or make them public. However, the SISSL is unique among OSI-approved licenses in requiring that "The Modifications which You create must comply with all requirements set out by the Standards body in effect one hundred twenty (120) days before You ship the Contributor Version." If the Modifications do not comply, SISSL becomes a copyleft license, and source must be published "under the same terms as this license [SISSL] on a royalty-free basis within thirty (30) days."
Common Development and Distribution License (CDDL) is a free and open-source software license, produced by Sun Microsystems, based on the Mozilla Public License (MPL). Files licensed under the CDDL can be combined with files licensed under other licenses, whether open source or proprietary. In 2005 the Open Source Initiative approved the license. The Free Software Foundation (FSF) considers it a free software license, but one which is incompatible with the GNU General Public License (GPL). In 2018, according to Black Duck Software the CDDL is the 16th most popular FOSS license, after the AGPLv3.
In 2006, a branding issue developed when Mike Connor, representing the Mozilla Corporation, requested that the Debian Project comply with Mozilla standards for use of the Thunderbird trademark when redistributing the Thunderbird software. At issue were modifications not approved by the Mozilla Foundation, when the name for the software remained the same.
This is a comparison of published free software licenses and open-source licenses. The comparison only covers software licenses with a linked article for details, approved by at least one expert group at the FSF, the OSI, the Debian project or the Fedora project. For a list of licenses not specifically intended for software, see List of free content licenses.
The Sybase Open Watcom Public Licence is a software license that has been approved by the Open Source Initiative. It is the licence under which the Open Watcom C/C++ compiler is released.
GNU IceCat, formerly known as GNU IceWeasel, is a free software rebranding of the Mozilla Firefox web browser distributed by the GNU Project. It is compatible with GNU/Linux, Windows, Android and macOS.
A free-software license is a notice that grants the recipient of a piece of software extensive rights to modify and redistribute that software. These actions are usually prohibited by copyright law, but the rights-holder of a piece of software can remove these restrictions by accompanying the software with a software license which grants the recipient these rights. Software using such a license is free software as conferred by the copyright holder. Free-software licenses are applied to software in source code and also binary object-code form, as the copyright law recognizes both forms.
The GNU Free Documentation License is a copyleft license for free documentation, designed by the Free Software Foundation (FSF) for the GNU Project. It is similar to the GNU General Public License, giving readers the rights to copy, redistribute, and modify a work and requires all copies and derivatives to be available under the same license. Copies may also be sold commercially, but, if produced in larger quantities, the original document or source code must be made available to the work's recipient.
A free license or open license is a license agreement which contains provisions that allow other individuals to reuse another creator's work, giving them four major freedoms. Without a special license, these uses are normally prohibited by copyright law or commercial license. Most free licenses are worldwide, royalty-free, non-exclusive, and perpetual. Free licenses are often the basis of crowdsourcing and crowdfunding projects.
Software relicensing is applied in open-source software development when software licenses of software modules are incompatible and are required to be compatible for a greater combined work. Licenses applied to software as copyrightable works, in source code as binary form, can contain contradictory clauses. This requirements can make it impossible to combine source code or content of several software works to create a new combined one.
