Guide to understand which license to choose when opening open source software "Choose a License"

Source code will be releasedOpen source software(OSS) is often the thing that fosters the willingness of creation by others or the foundation of new creation things, OSS is extremely important for the development of software. For OSS publication, the author can give "license" notation that can specify the scope of use of source code, but it is difficult to understand which license should be chosen together. A guide page that allows a programmer who exposes OSS to search for a license that meets the purpose so that he can choose his / her desired license "Choose a License"Has been published.

Choose a open source license | Choose a License
https://choosealicense.com/


When you open the above page, you can access the summary of the license that meets the purpose.

◆ When you want to acknowledge free use very simply
If you want to widely provide your own source code and use it freely,MIT LicenseIt is best to say.


MIT License not only accepts private use but also allows commercial use, redistribution, and modification under the condition "display the name of OSS author (copyright notice)". There is also an advantage that the author does not take any responsibility for the act of using OSS. For software that uses MIT License,Babel,.NET Core,RailsAnd so on.

MIT License | Choose a License


◆ When there is a patent concern
If you want to have OSS freely available and the patents owned by authors are used in OSS, "Apache License 2.0"Is recommended.


It is the same Apache License 2.0 as MIT License in that it allows free secondary use on the condition of copyright notice, but patent technology of the author included in OSS is also allowed to use OSS users for patent use Varies. For software that uses Apache License 2.0,Kubernetes,PDF.js,Swiftthere is.

Apache License 2.0 | Choose a License


◆ When expecting improvement by share
If you want to freely distribute the released OSS by allowing anyone to use, modify, redistribute it, accept the modification and redistribution by secondary usage while maintaining the copyright "Copy left"As a formGNU GPLv 3"License is appropriate.


Although the contents accepted for secondary use are the same as those of Apache License 2.0, the condition that "allow copying and freedom to change" is handed over to the software to be used secondarily. For software that uses GNU GPLv3,Ansible,Bash,GIMPthere is.


◆ When it is not software
Open source licenses are available for things that are not software.


· Data, media
Accept free use without conditions "CC 0 - 1.0"And request clear clarification of copyright indication and change points"CC-BY-4.0"Request until the handover of the same content license"CC-BY-SA-4.0"And so on.

· Software documentation
"Software documentation" of the document accompanying software is the same as the above data and media. However, care should be taken in software documentation that source code examples can only be used based on software licenses.

·font
Regarding fonts, licenses permitting free use of other works "SIL Open Font License 1.1"there is.

Non-Software Licenses | Choose a License
https://choosealicense.com/non-software/


◆ When you do not want to select a license
If you do not want to choose a license in the first place, it is ant, "I do not do anything".


However, since copyrighted material is generated as well as software code, if copyright is issued at the same time, if it is made public without showing licenses, fear of risk of litigations from the rightful owner and allow others to freely It can not be copied, modified, or redistributed. Care must be taken that the act of "not licensing" may result in unintended consequences of "prohibiting reuse of code at all".

The repository publishing service like GitHub contains the content that the other party will agree to fork in the service terms of use, so it can be offered to the world as OSS without the explicit license. In addition, in the case that you want if completely removed and restricted by the copyright "Public domainIt is also a hand to provide as.

◆ Other options
Besides the above license type, "GNU AGPLv 3"GNU LGPLv 3"Mozilla Public License 2.0"Etc. are summarized on the following pages.

Licenses | Choose a License
https://choosealicense.com/licenses/