Common license agreements in the open source domain and the differences between them

More and more developers and designers want to open up their own products so that others can do more with their code, and the open source community is so vibrant. In the areas of application we can think of, there are open source software (like Wordpress,drupal these open source CMS). However, many people do not understand the open source license, this article describes the open source domain commonly used in several license agreements and the difference between them.

What is a license agreement?

What is a license, when you issue a license for your product, you are in the transfer of your rights, however, you still have the copyright and patent (if you apply), the purpose of the license is to use your product to provide certain permissions.

Whether the product is distributed to the public free of charge, or sell, a license agreement is very useful, otherwise, for the former, you are tantamount to giving up all of your rights, no one is obligated to show your original author identity, for the latter, you will have to spend more than develop more energy to deal with the user's licensing issues.

and the open source license makes these things easier, and it's easy for developers to contribute their own code to a project, and it protects the identity of your original author, giving you at least an endorsement, and open source licenses can prevent others from keeping a product for themselves. Here is the open source world's 5 big license agreement.

GNU GPL

The GNU general public Licence (GPL) is probably the most common licensing mode in the open source world. The GPL guarantees the rights of all developers, while providing sufficient copies, distributions, and modifications to the user:

• Free to copy
  You can copy the software to your computer, your client's computer, or anywhere. There are no restrictions on the number of copies.
• Free to distribute
  Provide downloads on your site, copy to a U disk, or print out the source code and throw it out the window (for environmental reasons, please don't do this).
• Can be used for profit
  You can charge for distributing the software, but you must provide your client with the GNU GPL license Agreement before charging, so that they know that they can get the software free from other channels and why you charge.
• can be modified freely
  If you want to add or remove a feature, no problem, if you want to use some of the code in other projects, there is no problem, the only requirement is that the project using this code must also use the GPL protocol.

It should be noted that when distributing, you need to explicitly provide source code and binary files, in addition, some of the protocols for some programs have some problems and limitations, you can look at the @PierreJoye written practical Guide to GPL Compliance. Using the GPL protocol, you must include the appropriate information in the source code, as well as the protocol itself.

GNU LGPL

GNU also has another protocol, called LGPL (Lesser General public Licence), which has less rights to the product than the GPL, and generally LGPL for open source libraries or frameworks for non-GPL or non-open-source products. Because the GPL requires that products that use GPL code must also use the GPL protocol, developers are not allowed to use GPL code for commercial products. The LGPL bypassed the restriction.

Bsd

BSD has fewer restrictions on software distribution than other open source protocols, such as the GNU GPL. There are several versions of the agreement, the main version of which is two, the new BSD protocol and the simple BSD protocol, both of which have been amended to be compatible with the GPL and approved by the Open-source organization.

The new BSD protocol (3 clause agreement) has no restrictions on software distribution except that it requires a copyright notice and disclaimer. In addition, the Agreement prohibits the endorsement of derivative products in the name of the developer, but the simple BSD agreement removes the clause.

MIT

The MIT agreement may be one of the most liberal of the big open source agreements, with the core terms:

The software and related documents are free to all people and can be disposed of arbitrarily, including use, reproduction, modification, merging, publication, distribution, authorization, or sale. The only limitation is that the software must contain the above copyright and license hints.

This means:

• You are free to use, copy, modify, and can be used for your own projects.
• can be distributed free of charge or used for profit.
• The only limitation is that the license declaration must be included.

The MIT protocol is one of the most permissive of all open source licenses, with no restrictions other than the need to include a license statement.

Apache

Compared to other open source protocols, the Apache Protocol 2.0 has a patent license, which is best for developers involved in proprietary content (here's an article on this issue), in addition to licensing the user with a copyright.

The Apache protocol also has the following areas to note:

• Permanent rights
  Once authorized, permanently owned.
• Global scope of rights
  Be authorized in one country and apply to all countries. If you are in the United States, the license is authorized from India, there is no problem.
• Authorization is free and no royalty
  In the early stage, there is no cost in later period.
• Grant without exclusivity
  Anyone can get an authorization.
• Authorization cannot be undone
  Once authorized, no one can cancel. For example, if you develop a derivative based on the product code, you don't have to worry about being banned from using the code one day.

The distribution code contains a number of requirements, mainly to be recognized in the declaration for the person participating in the development and to include a copy of the license agreement.

Creative Commons

Creative Commons (CC) is not strictly open source license, it is mainly used for design. Creative Commons has a variety of protocols, each of which provides the appropriate licensing mode, and the CC protocol consists of 4 basic forms:

• Signature Right
  Must be signed by the original author before it can be modified, distributed, copied.
• Remain consistent
  Works can also be modified, distributed and replicated on the basis of the CC agreement.
• Non-commercial
  Works can be modified, distributed, reproduced, but not used for commercial purposes. However, the definition of business is somewhat vague, for example, some people think that non-commercial use refers to not sell, some think it is not even in the advertising site, and some people think non-commercial means non-profit.
• Can't derive new works
  You can copy, distribute, but not modify, or create your own work based on it.

These licensing forms can be combined, with the toughest combination being "signed, non-commercial, not derivative", meaning that you can share the work, but not change it or make it profitable, and must be signed by the original author. In this licensing mode, the original author also has full control of the work, and the most lenient combination is "signature", meaning, as long as the original author signed, you can freely dispose of.

Extending resources

• Creative Commons Licenses
  Official terms and interpretations of Creative Common license
• Open Source Initiative
  Includes various open source protocol resources
• Open Source Licenses Comparison
  A comparison of mainstream open source protocols
• Understanding Open-source Licensing
  Open Source Protocol Detailed
• How To:pick an Open Source License
  How to choose a different open source protocol

This article international sources: Smashing Magazine A short Guide to Open-source and Similar Licenses