Q: There seem to be several licenses for open source projects, but which license should I choose?
A: In regards to the software, there are several major licenses, so please refer to the following chart to choose a license that best matches your goals.
| Phase for adding a license to your software and distributing it | Phase for using software with a license by another person to create your own software | |
|---|---|---|
| GPL version 2.0/3.0 | - It is not possible to prohibit derivative works by people that have received the software. - If the people that have received the software adhere to the GPL, they can license/transfer the software for compensation. - You have an obligation to provide the source in the event that information was transferred via a format other than the source code format (it is not possible to distribute binary code only). - It is possible to append additional conditions, however, a) Any conditions that are more restrictive than the GPL are invalid b) Even if valid, people that have received the software are free to remove such conditions, and furthermore, distribute to a third party. - In the event that technological protection measures are in place, it is not possible to prohibit evasion of said measures (3.0). - You must also grant a license for patents as well (3.0). |
- You are free to make derivative works, but in principle, you must publish the works according to the conditions of the GPL. - It is possible to append additional conditions, however, a) Any conditions that are more restrictive than the GPL are invalid b) Even if valid, people that have received the software are free to remove such conditions, and furthermore, distribute to a third party. - In regards to non-GPL portions that were simply attached to the GPL portions, control is free through individual licenses. |
| LGPL version 3 | - A license that uses the basic GPL as a basis, and has added a partial modification in anticipation of use as a library. - Adding conditions that prohibit alterations, etc. to libraries that are protected by GPL licenses violates the GPL. However, in the LGPL, there are provisions to the effect that do not limit the conditions of duplication or transmission of combined works (derivative works) as long as you do not alter the conditions prohibiting the alteration, etc. of protected libraries. For this reason, it is possible to set free conditions, including prohibition of commercial use, etc. - In the event that you apply this license to your own original works, prohibition of alterations, etc. is not possible. - In the event that people that have received the software link original works with other things (non-LGPL) (derivative works), they are free to set individual conditions for non-LGPL portions (in other words, unlike the GPL, the license does not necessary cover the entirety of the derivative works). - You will grant a license to patents. - It is possible to prohibit evasion of technical measures. |
- For linked works (derivative works), as long as modifications to library portions protected by the GPL license are not prohibited, it is possible to set free conditions |
| Apache 2.0 | - You must make the setting of an indefinite period, setting of free of cost, setting of non-exclusion, duplication, creation, publication, execution, sub-licensing, distribution, creation of derivatives open. - When distributing, it is necessary to attach a copy of the license. - Make it so that it is clear who changed the files. - In the event that people who received the software create derivative works, individual licenses for the derivative works are possible. - You will grant a license to patents (in the event you initiate patent litigation, the license becomes invalid). - It is possible to distribute only the binary code. - Prohibition of commercial use is possible. |
- For derivative works, it is possible to add free conditions, including prohibition of commercial use. |
| MIT | - Details that copyright notice must be documented in software packaging (duplicates) or in important portions. - There is a disclaimer notifying that the license is without guarantee. - You will be providing the people who received the software with usage that is free of cost and free of restraints. - It is possible to distribute only the binary code. - Prohibition of commercial use is possible. |
- For derivative works, it is possible to add free conditions, including prohibition of commercial use. |
For the hardware, Creative Commons Licenses have been abundantly used as an open source license for 3D data. However, in regards to the hardware, there are many cases where copyright does not apply, and there are discussions of whether Creative Commons Licenses are appropriate for licenses for hardware. The CERN Open Hardware License, among others, is available as a license specialized to open source hardware, but it seems that there are no licenses that are as established as software licenses.
Q: I would like people to use my work for non-commercial purposes as much as possible, but I am also thinking of establishing a separate commercial license for commercial usage. Can I use these terms of use in that case too?
A: Yes. When you provide a license that permits non-commercial usage, it is possible to establish a separate commercial license. For example, when you provide a CC BY-NC license that permits non-commercial usage, this CC license is simply the conditions for when a person uses the work without permission from the rights holder. So it is possible for the user to contact the rights holder, and receive permission for commercial use, and it is also possible for the rights holder to preliminarily juxtapose the non-commercial license and the commercial license. When thinking about commercial usage, it does not just entail only publishing the software and data; designing a commercial license so it is easy to understand, displaying a contact name for commercial usage, and displaying that the work is open for commercial purposes are points you must consider.
Q: What kinds of risks should be taken into consideration for product liability? Also, if I use these terms of use, can I avoid all of those risks?
A: For defects in the software and data, the rights holder being held liable for product liability is an exceptional case. In Product Liability Law, it is possible to be held liable for “defects in the design,” but in Section 6.2 of these terms of use, the rights holder’s exemption from liability is stipulated. At the same time, there is the opinion that stipulations of Product Liability Law are mandatory provisions that cannot be overwritten by a contract between parties, and there is also the opinion that, should you follow the former opinion, the rights holder will not be exempt from liability according to Product Liability Law, even under the these terms of use. For details, please refer to the guidelines and report for the “Investigative session for foundation planning of a FAB society” which was held by the Institute for Information and Communications Policy.
Ministry of Internal Affairs and Communications: http://www.soumu.go.jp/menu_news/s-news/01iicp01_02000030.html (Japanese only)
Report: http://www.soumu.go.jp/main_content/000361195.pdf (Japanese only)
Guidelines: http://www.soumu.go.jp/main_content/000361196.pdf (Japanese only)