1. The overall structure diagram of GPL, BSD , MIT, Mozilla, Apache and LGPL is as follows:
2. Protocol details
LGPL open source license:
LGPL is an open source agreement of GPL designed mainly for class library use. It is different from the GPL that requires any software that uses/modifies/derived the GPL class library to adopt the GPL agreement. LGPL allows commercial software to use the LGPL class library through the class library reference (link) without requiring the code of open source commercial software. This enables the open source code using the LGPL agreement to be referenced, published and sold by commercial software as a class library.
However, if the code or derivatives of the LGPL agreement is modified, all modified codes, additional codes and derived codes involving the modified part must adopt the LGPL agreement. Therefore, the open source code of the LGPL protocol is very suitable for being referenced by commercial software as a third-party library, but it is not suitable for commercial software that wants to use the LGPL protocol code as the basis for secondary development through modification and derivatives.
Both GPL / LGPL protect the intellectual property rights of the original author, preventing someone from using open source code to copy and develop similar products.
Mozilla Open Source License:
The Mozilla License is a free , open source , detailed software license developed and maintained by the Mozilla Foundation . The agreement combines the characteristics of the BSD license and the GNU General Public License agreement , and seeks to balance the concerns of developers of proprietary software and open source software.
The MPL is used to license Mozilla Firefox , Mozilla Thunderbird , and other Mozilla software , but is also used by other products such as Adobe 's Flex product line, and LibreOffice 4.0 (which also uses LGPL 3+). Version 1.1 has also been deliberately adapted into derivative licenses by companies such as Sun Microsystems ' General Development and Distribution License .
GPL open source license:
The Linux we are very familiar with adopts the GPL . The GPL agreement is very different from BSD , Apache License and other licenses that encourage code reuse. The starting point of GPL is the open source/free use of code and the open source/free use of quoted/modified/derived code, but the modified and derived code is not allowed to be released and sold as closed-source commercial software . This is why we can use various free linux, including commercial company linux and various free software developed by individuals, organizations, and commercial software companies on linux .
The main content of the GPL agreement is that as long as the product of the GPL agreement is used in a software ("use" refers to class library references, modified codes or derivative codes), the software product must also adopt the GPL agreement, which must be open source and free. . This is called "contagion". There is no problem in using a product under the GPL agreement as a separate product, and you can also enjoy the advantage of being free.
Since the GPL strictly requires that software products using the GPL class library must use the GPL agreement, for open source code using the GPL agreement, commercial software or departments that have confidentiality requirements for the code are not suitable for integration/adoption as the basis for class libraries and secondary development .
Other details, such as the need to accompany the GPL agreement when re-released, are similar to BSD / Apache .
BSD open source license:
The BSD license was originally used on the 4.4BSD/4.4BSD-Lite versions published by the University of California, Berkeley (BSD is the abbreviation of Berkly Software Distribution), and it was gradually used later. In 1979, the University of California, Berkeley released BSD Unix, known as the pioneer of open source code , and the BSD license was developed along with BSD Unix. The BSD license is adopted by open source software such as Apache and the BSD operating system.
Compared with the strictness of the GPL license and the MPL license, the BSD license is much more relaxed. It also only needs to attach the original text of the license, but what is more interesting is that it also requires all further developers to transfer their copyrights. Put the information on it, so you may encounter a small situation when you get the software released under the BSD license, that is, the space occupied by these copyright material licenses is larger than the program.
MIT Open Source License:
MIT is a license agreement as broad as BSD , and the author only wants to retain the copyright without any other restrictions. That is, you must include a statement of the original license agreement in your distribution, whether you distribute it as binary or source code. The MIT agreement, also known as the proprietary software license, was originally developed by the Massachusetts Institute of Technology. Rights of the authorized person: 1. The authorized person has the right to use, reproduce, modify, merge, publish, distribute, sublicense and sell software and copies of the software. 2. The licensee can modify the authorization terms to the appropriate content according to the needs of the program. Licensee Obligations: The software and all copies of the software must contain copyright notices and license notices.
Apache Open Source License:
Apache is a free software license released by the Apache Software Foundation , originally written for the Apache http server. The Apache License requires licensees to retain copyright and disclaim their rights, but it is not an anti-copyright license.
The Apache License is widely used within and outside the Apache community. All projects under the Apache Foundation use the Apache License, and many non-Apache Foundation projects also use the Apache License: According to statistics, as of October 2012, there were 8,708 projects using the Apache License on sourceforge .