Open Source Licensing Introduction

Apache v2 License

Apache licence is the protocol used by the famous non-profit open source organization Apache. The agreement is similar to BSD, encouraging code sharing and respecting the authorship of the original author, as well as allowing the code to be modified and republished (as open source or commercial software). The conditions that need to be met are similar to BSD:

The user who needs to give the code a copy of Apache Licence
If you modify the code, it needs to be modified again in the file described. In the
extended code (modified and in code derived from the source code) need to have the original code of the Agreement, trademarks, patent statements and other original author rules need to include the instructions.
If the rereleased product contains a notice file, the Apache Licence is required in the notice file. You can add your own permission to the notice, but you may not be able to make changes to Apache licence.

Apache licence is also a friendly license for commercial applications. Users can also modify the code as needed to meet their needs and publish/sell as open source or commercial products. MIT License

The MIT license is derived from MIT (Massachusetts Institute of Technology, MIT), also known as "x terms" (X License) or "x11 terms" (X11 License)

MIT content is quite similar to the content of the three BSD license (3-clause BSD license), but gives the software a greater right and less restriction on the authorized person.

The authorized person has the right to use, reproduce, modify, merge, publish, distribute, redistribute, license and sell copies of software and software.

The authorized person may modify the authorization terms to the appropriate content according to the requirements of the program.

Copyright notices and license notices must be included in all copies of the software and software.

This license is not a copyleft free software license, and is permitted in free/open source software or non-free software (proprietary software).

This is also an essentially different place for MIT and BSD (the BSD license, 3-clause BSD license).

The MIT terms may coexist with other license terms. In addition, the MIT terms are also licensed by the Free Software Foundation (FSF), which are compatible with the GPL. GPL v2

We are familiar with the use of Linux is the GPL. Licenses that encourage code reuse, such as the GPL and BSD, Apache licence, are very different. The starting point of the GPL is the code of open source/free use and citation/modification/derivative code of Open source/free use, but does not allow the modification and derivative of the code to be released and marketed as closed source commercial software. That's why we can use a variety of free Linux, including free software developed by individuals, organizations, and commercial software companies on Linux and Linux in commercial companies.

The main content of the GPL agreement is that the SOFTWARE product must also be licensed under the GPL, both open source and free, as long as it is used in a software ("Use" refers to a class library reference, modified code or derivative code) of the GPL-based product. This is known as "contagious". GPL products are used as a standalone product without any problems and can also enjoy the benefits of free.

Since the GPL is strictly required for software products that use the GPL class library, it is not appropriate for an open source code that uses the GPL agreement to use a business software or a department that has confidentiality requirements for the code to integrate/adopt as the basis for a class library and two development.

Other details, such as Bsd/apache, need to be accompanied by the GPL and other similar issues. Artistic License 2.0

Artistic License, also known as the Art License Agreement (English: Artistic License), usually refers to the original art License Agreement (version 1.0), which is a free software licensing term primarily used in the official Perl interpreter and most CPAN modules. The original art license agreement was written by Larry Wall, the founder of Perl. BSD 2-clause License

BSD allows the user to modify and republish the code (in the form of other protocols), allowing closed source commercial release and sales.

BSD encourages code sharing while respecting the copyright of the author of the Code.

With the BSD protocol, the following rules apply:

The redistribution of the product contains the source code, the source code must be in the original code of the BSD protocol,
if the redistribution is only a binary class library/software, you need to be in the class library/software document that and the copyright notice contains the original code in the BSD protocol.

Affero GPL

is a widely used free software concession clause, originally written by Affero, Inc. The latest version of this concession clause is "3rd edition" (V3), released in November 2007. Affero general Public License terms are changed from the GNU General Public License Terms and additional terms are added in order to apply the Copyleft terms to applications running on the network (such as Web applications), thereby avoiding the use of an app service provider to evade the GNU General Public License terms. Affero GPL

is a widely used free software concession clause, originally written by Affero, Inc. The latest version of this concession clause is "3rd edition" (V3), released in November 2007. Affero general Public License terms are changed from the GNU General Public License Terms and additional terms are added in order to apply the Copyleft terms to applications running on the network (such as Web applications), thereby avoiding the use of an app service provider to evade the GNU General Public License terms. LGPL v2.1

LGPL is a GPL-open source protocol designed primarily for use in class libraries. And the GPL requires that any software that uses/modifies/derives from the GPL library must be different from the GPL agreement. LGPL allows commercial software to use the LGPL class library through the Class Library Reference (link) without the need for code for open source commercial software. This allows open source code with the LGPL protocol to be referenced and published and sold as a class library by commercial software.

However, if you modify the code or derivation of the LGPL protocol, all the modified code, the additional code involved in the modification, and the derived code must adopt the LGPL protocol. The open source code of the LGPL protocol is therefore well suited to be referenced by commercial software as a third-party class library, but it is not intended to be used as a commercial software that is developed two times through modification and derivation, based on LGPL protocol code.

GPL/LGPL protects the intellectual property of the original author and avoids the use of open source code to replicate and develop similar products BSD (3-clause) License

BSD allows the user to modify and republish the code (in the form of other protocols), allowing closed source commercial release and sales.

BSD encourages code sharing while respecting the copyright of the author of the Code.

With the BSD protocol, the following rules apply:

Re-release of the product contains the source code, in the source code must have the original code in the BSD protocol;
If you redistribute only binary class libraries/software, you need to include the BSD protocol in the original code in the documentation for the class library/software and the copyright notice;
You may not use the source code "author/Institution name" or "Original product name" to do marketing promotion. Eclipse Public License v1.0

EPL allows the user to use, reproduce, distribute, transmit, display, modify and change the two commercial releases of the closed source.

With the EPL protocol, the following rules apply:

1. When a code contributor publishes the whole or part of the source again and again, it must continue to follow the EPL open source agreement for publishing, rather than using other protocols. Unless you are authorized by the original "source" owner;
under 2.EPL protocol, You can publish the source code without making any changes. But if you want to post the modified source code, or when you re-publish the binary, you have to declare that its source code is available, and to inform the acquisition method;
3. When you need to EPL the source code as a part of the other private source mixed with the other to become a project release, you can put the entire project/product as a private agreement, but to declare which part of the code is EPL, and declare that part of the code continues to follow EPL;
4. Independent modules (separate module), no need for open source.

LGPL v3

As opposed to LGPL v2, users are not only required to publish the modified source code, but also to publish related hardware. Mozilla public License Version 2.0

The MPL is a shorthand for the Mozilla Public License, a software license designed by Mozilla Group Netscape in early 1998 for its open source software projects. The most important reason for the MPL license is that Netscape believes that the GPL license does not well balance the developer's need for source code and the benefits they derive from using the source code. Compared to the famous GPL license and BSD license, the MPL is the same as many of the rights and obligations (because they are all open source software licenses that are OSIA certified). However, there are several notable differences in MPL compared to the following:

· The MPL requires that modifications to the source code issued by the MPL license be re-licensed in the form of an MPL license to ensure that other people can share the source under the MPL's terms. However, the definition of "release" in the MPL License is "file published as source code", which means that the MPL allows an enterprise to add an interface to its existing source code base, except that the source of the interface program is licensed in the form of an MPL license, The source code repository can be used to force external licensing without the MPL license. These, for reference to other people's source code for their own business software development behavior left a gap.
· The MPL License in section 7th allows licensee to mix the source code obtained by the MPL license with its own other types of code to obtain its own software program.
• With respect to the software patent, the MPL license does not expressly oppose the software patent as the GPL license does, but expressly requires that the source code provider be unable to provide sources that are already protected by the patent (unless he is a patent owner, and the source code is freely licensed to the public in writing), It is also not possible to apply these source code licenses in the form of an open source license before applying for patents related to these source codes.
• Definition of source code in the MPL (1.1 version) license, the source code is defined as: "The source code refers to the modification of the work of the highest priority playable form, which includes: all modules of all the source program, plus the definition of the interface, plus control of the installation and compilation of executable works ' Originally ' Script ', or not significantly different from the original source code is the source code contributor selected from the public domain can get the program code. "
• MPL License 3rd There is a special section on the source code changes to describe the provisions, that is, all the re-publishers have to have a special file on the source code changes in the time and the way the changes are described.

GPL v3

The GPL v3 is similar to the GPL v2. The difference is that the user is not only required to publish the modified source code, but also to publish the relevant hardware. Public Domain

Public Domain is a part of human work and a part of knowledge, can include articles, art, music, science, inventions and so on. For intellectual property in the domain, no individual or group has all rights (all rights are usually embodied by copyright or patent). These knowledge inventions belong to the public cultural heritage and can be used and processed without restriction by any person (without regard to the law on security, export, etc.). The original intention of the copyright system was to encourage the author to engage in creation by giving the creator a period of exclusive rights as a stimulus. When the period of exclusive rights is over, the work enters the public domain. In the public domain, the public has the right to use them freely because there are no exclusive rights holders.