Permissive open source license
A generous open source license (English original term Permissive license ) is an open source license that allows a broader reuse of licensed content than strict copyleft licenses such as the GNU General Public License (GPL). Such a license offers many of the same features that other open source licenses offer. In contrast to non-revealing licenses , all derivative works and copies of the source code under such a license can be published and distributed under rules and conditions that are more restrictive or have fundamentally different properties than those of the original license . In other words: derivations of source code under a permissive license do not have to be published under the same license as the original source code, but may, for example, be processed into proprietary software .
Well-known examples of permissive licenses are the MIT license and the BSD license .
Compared to the public domain
Computer Associates Int'l v. Altai used the concept of Public Domain ( English public domain , all copyrights go to the general public over) to refer to works that are very far, but common among permission are referred to the contrary to work that deliberately into the public domain. Such licenses are actually not equivalent to the public domain.
Permissive licenses often stipulate some limited obligations, such as that the original author must be named (attribution) . If a work is actually in the public domain, this is normally not necessary from a legal point of view, but naming the author of a work is e.g. B. viewed as an ethical duty in academia.
GPL compatibility
Some permissive licenses contain clauses requiring the licensee to mention the original author when promoting the derivative product. These clauses are called advertising clauses . An example using the PHP license: If a product is published that is derived from PHP , it must always be mentioned that it is derived from PHP, especially when promoting this new product. Licenses with an advertising clause include the 4-clause BSD license , the PHP license and the OpenSSL license . These licenses, while permissive licenses (in that they do not prohibit proprietary published derivatives), are incompatible with the widely used GPL (which prohibits such derivatives; derivatives of GPL works must be published under the GPL).
Examples of permissive licenses without advertising clauses are the MIT license , the 3-clause BSD license , the zlib license and all versions of the Apache license except version 1.0.
It is fundamentally possible to transfer permissive licenses to the GPL. The Apache license does not prohibit the licensing of modifications or derivatives in any other way. The Apache software license 2.0 is accordingly compatible with the GPL version 3.0. The GNU project offers a compatibility overview of numerous licenses. This gives recommendations for choosing a license that is compatible with the GPL.
Some licenses prohibit derivative works from adding a restriction that prohibits a redistributor from introducing other or more restrictions. The purpose of such clauses is to prohibit redistribution under the GPL or similar copyleft licenses. There are many examples of such licenses, such as the CDDL and the Ms-PL . Such restrictions always make a license incompatible with the GPL.
Web links
Individual evidence
- ↑ http://www.apache.org/licenses/GPL-compatibility.html. May 12, 2016. Retrieved May 12, 2016 .
- ↑ Various licenses and comments. Retrieved May 12, 2016 .
