Introduction of open source agreement GPL/LGPL/BSD/MIT/Apache/Mozilla/Eclipse/CC

Introduction of open source agreement GPL/LGPL/BSD/MIT/Apache/Mozilla/Eclipse/CC

The open source license agreement makes it easy for developers to contribute their own code to a project. It can also protect your original author's identity and make you at least recognized (regardless of whether the product is distributed to the public for free or sold). The open source license agreement can also prevent Others take a product as their own.

Overview

1 、 GNU GPL

GNU General Public License (GPL) is probably the most commonly used licensing model in the open source community. GPL guarantees the rights of all developers, and at the same time provides users with sufficient rights to copy, distribute, and modify:

• Free to copy
  You can copy the software to your computer, your client's computer, or anywhere. There is no limit to the number of copies.
• Can be distributed freely
  Provide downloads on your website, copy them to a USB flash drive, or print out the source code and throw it out of the window (for environmental protection, please don’t do this).
• It can be used for profit.
  You can charge when distributing the software, but you must provide your customers with the GNU GPL license agreement of the software before charging, so that they know that they can get the software for free from other channels, and The reason for your charge.
• Can be modified freely.
  If you want to add or delete a function, no problem, if you want to use part of the code in other projects, no problem, the only requirement is that the project using this code must also use the GPL agreement.

It should be noted that the source code and binary files need to be clearly provided when distributing. In addition, some protocols used for certain programs have some problems and limitations. You can read the  article Practical Guide to GPL Compliance written by  @PierreJoye . To use the GPL agreement, you must include the corresponding information in the source code, as well as the agreement itself.

2 、 GNU LGPL

GNU also has another agreement called LGPL ( Lesser General Public Licence ), which reserves fewer rights to products than GPL. In general, LGPL is suitable for open source libraries or frameworks for non-GPL or non-open source products. . Because of GPL requirements, products that use GPL code must also use the GPL agreement, and developers are not allowed to use GPL code for commercial products. The LGPL bypasses this restriction.

3 、 BSD

BSD has fewer restrictions on software distribution than other open source agreements (such as GNU GPL). There are many versions of the agreement, the most important version has two, the new BSD agreement and the simple BSD agreement, these two agreements have been revised, compatible with the GPL, and recognized by open source organizations.

The new BSD agreement (3-clause agreement) has no restrictions on software distribution, except for the need to include a copyright notice and a disclaimer. In addition, the agreement also prohibits the use of the developer's name to endorse derivative products, but the simple BSD agreement deletes this clause.

4 、 WITH

The MIT agreement may be the loosest of several open source agreements. The core clauses are:

The software and related documents are free to everyone and can be disposed of at will, including use, copy, modify, merge, publish, distribute, sublicense, or sell. The only restriction is that the software must contain the above copyright and permission notices.

this means:

• You can freely use, copy, modify, and use it for your own projects.
• It can be distributed for free or used for profit.
• The only restriction is that a license statement must be included.

The MIT agreement is the most permissive of all open source licenses, and there are no restrictions except that the license statement must be included.

5、Apache

Compared with other open source agreements, Apache Protocol 2.0 not only provides users with copyright licenses, but also patent licenses. For developers who involve patent content, this agreement is the most suitable ( here is an article on this issue ).

The Apache protocol also has the following points that need to be explained:

• Permanent rights
  Once authorized, permanent possession.
• Global rights
  are authorized in one country and apply to all countries. If you are in the U.S. and the license is granted from India, there is no problem.
• The authorization is free, and
  there is no royalties. There are no fees for the early and late periods.
• Authorization is not exclusive,
  anyone can get authorization
• Authorization is irrevocable
  Once authorization is obtained, no one can cancel it. For example, if you develop a derivative product based on the product code, you don't have to worry about being banned from using the code one day.

There are some requirements for distributing the code. The main thing is that the people involved in the development should be recognized in the statement and a copy of the original license agreement should be included.

6、MPL (Mozilla Public License 1.1)

The MPL agreement allows free redistribution and free modification, but requires the copyright of the modified code to belong to the initiator of the software. This kind of authorization maintains the interests of commercial software, and it requires the free contribution of copyright to the software based on the modification of this software. In this way, the copyright of all code surrounding the software is concentrated in the hands of the initiator. However, MPL is allowed to be modified and used free of charge. MPL software has no requirements for linking.

7、EPL (Eclipse Public License 1.0)

EPL allows Recipients to arbitrarily use, copy, distribute, spread, display, modify, and modified closed-source secondary commercial releases.

To use the EPL protocol, you need to comply with the following rules:

• When a Contributors releases the entire or part of the source code as open source again, it must continue to follow the EPL open source agreement to publish, and cannot use other agreements to publish. Unless you have obtained the authorization of the original "source code" Owner;
• Under the EPL agreement, you can release the source code commercially without any modification. But if you want to release the modified source code, or when you re-release the Object Code, you must declare that its Source Code is available. And to inform the acquisition method;
• When you need to mix the source code under the EPL as a part with other private source code into a project release, you can release the entire Project/Product under a private agreement, but you have to declare which part of the code is under the EPL, and declare That part of the code continues to follow EPL;
• 4. Separate Module (Separate Module), no need to open source.

8. Creative Commons knowledge sharing agreement

Creative Commons (CC) is not strictly an open source license, it is mainly used for design. Creative Commons has a variety of agreements, each of which provides a corresponding licensing model. The CC agreement mainly includes 4 basic forms:

• 
  Attribution rights must be signed by the original author before they can be modified, distributed, or copied.
• Keep consistent The
  works can also be modified, distributed, and copied on the basis of the CC agreement.
• Non-commercial
  works can be modified, distributed, copied, but cannot be used for commercial purposes. However, the definition of business is somewhat vague. For example, some people think that non-commercial use means that it cannot be sold, some think that it cannot even be placed on a website with advertisements, and some people think that non-commercial means non-profit.
• New works
  can not be derived. You can copy and distribute, but you cannot modify or create your own works based on this.

These forms of permission can be combined. The most stringent combination is "signature, non-commercial, no new works can be derived", which means that you can share the work, but you can't modify it or make money from it, and you must sign the original author. Under this licensing model, the original author still has complete control over the work, and the loosest combination is "signature", which means that as long as the original author is signed, he can dispose of it freely.