Copyright alternativesVarious copyright alternatives in an alternative compensation systems (ACS) have been proposed as ways to allow the widespread reproduction of digital copyrighted works while still paying the authors and copyright owners of those works. This article only discusses those proposals which involve some form of government intervention. Other models, such as the street performer protocol or voluntary collective licenses, could arguably be called "alternative compensation systems" although they are very different and generally less effective at solving the free rider problem.
Public-domain softwarePublic-domain software is software that has been placed in the public domain, in other words, software for which there is absolutely no ownership such as copyright, trademark, or patent. Software in the public domain can be modified, distributed, or sold even without any attribution by anyone; this is unlike the common case of software under exclusive copyright, where licenses grant limited usage rights.
Public-domain-equivalent licensePublic-domain-equivalent license are licenses that grant public-domain-like rights and/or act as waivers. They are used to make copyrighted works usable by anyone without conditions, while avoiding the complexities of attribution or license compatibility that occur with other licenses. No permission or license is required for a work truly in the public domain, such as one with an expired copyright; such a work may be copied at will.
Permission culturePermission culture is a term often employed by Lawrence Lessig and other copyright activists such as Luis Villa and Nina Paley to describe a society in which copyright restrictions are pervasive and enforced to the extent that any and all uses of copyrighted works need to be explicitly leased. This has both economic and social implications: in such a society, copyright holders could require payment for each use of a work and, perhaps more importantly, permission to make any sort of derivative work.
Anti-copyright noticeAn anti-copyright notice is a specific statement that is added to a work in order to encourage wide distribution. Such notices are legally required to host such specific media; under the Berne Convention in international copyright law, works are protected even if no copyright statement is attached to them. However, "anti-copyright" statements typically do not take the form of either sophisticated public copyright licenses or a simple dedication to the public domain; instead, they usually just encourage wide distribution.
Software licenseA software license is a legal instrument (usually by way of contract law, with or without printed material) governing the use or redistribution of software. Under United States copyright law, all software is copyright protected, in both source code and object code forms, unless that software was developed by the United States Government, in which case it cannot be copyrighted. Authors of copyrighted software can donate their software to the public domain, in which case it is also not covered by copyright and, as a result, cannot be licensed.
Apache LicenseThe Apache License is a permissive free software license written by the Apache Software Foundation (ASF). It allows users 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. The ASF and its projects release their software products under the Apache License. The license is also used by many non-ASF projects. Beginning in 1995, the Apache Group (later the Apache Software Foundation) released successive versions of the Apache HTTP Server.
Comparison of free and open-source software licensesThis comparison only covers software licenses which have a linked Wikipedia article for details and which are approved by at least one of the following expert groups: the Free Software Foundation, the Open Source Initiative, the Debian Project and the Fedora Project. For a list of licenses not specifically intended for software, see List of free-content licences. FOSS stands for "Free and Open Source Software". There is no one universally agreed-upon definition of FOSS software and various groups maintain approved lists of licenses.
MIT LicenseThe MIT License is a permissive free software license originating at the Massachusetts Institute of Technology (MIT) in the late 1980s. As a permissive license, it puts only very limited restriction on reuse and has, therefore, high license compatibility. Unlike copyleft software licenses, the MIT License also permits reuse within proprietary software, provided that all copies of the software or its substantial portions include a copy of the terms of the MIT License and also a copyright notice.
Free software movementThe free software movement is a social movement with the goal of obtaining and guaranteeing certain freedoms for software users, namely the freedoms to run, study, modify, and share copies of software. Software which meets these requirements, The Four Essential Freedoms of Free Software, is termed free software. Although drawing on traditions and philosophies among members of the 1970s hacker culture and academia, Richard Stallman formally founded the movement in 1983 by launching the GNU Project.
