The Open Source Definition (Annotated)

Rationale: By constraining the license to require free redistribution, we eliminate the temptation for licensors to throw away many long-term gains to make short-term gains. If we didn’t do this, there would be lots of pressure for cooperators to defect.

Rationale: We require access to un-obfuscated source code because you can’t evolve programs without modifying them. Since our purpose is to make evolution easy, we require that modification be made easy.

Rationale: The mere ability to read source isn’t enough to support independent peer review and rapid evolutionary selection. For rapid evolution to happen, people need to be able to experiment with and redistribute modifications.

Rationale: Encouraging lots of improvement is a good thing, but users have a right to know who is responsible for the software they are using. Authors and maintainers have reciprocal right to know what they’re being asked to support and protect their reputations.

Accordingly, an open source license must guarantee that source be readily available, but may require that it be distributed as pristine base sources plus patches. In this way, “unofficial” changes can be made available but readily distinguished from the base source.

Rationale: In order to get the maximum benefit from the process, the maximum diversity of persons and groups should be equally eligible to contribute to open sources. Therefore we forbid any open source license from locking anybody out of the process.

Some countries, including the United States, have export restrictions for certain types of software. An OSD-conformant license may warn licensees of applicable restrictions and remind them that they are obliged to obey the law; however, it may not incorporate such restrictions itself.

Rationale: The major intention of this clause is to prohibit license traps that prevent open source from being used commercially. We want commercial users to join our community, not feel excluded from it.

Rationale: This clause is intended to forbid closing up software by indirect means such as requiring a non-disclosure agreement.

Rationale: This clause forecloses yet another class of license traps.

Rationale: Distributors of open source software have the right to make their own choices about their own software.

Yes, the GPL v2 and v3 are conformant with this requirement. Software linked with GPLed libraries only inherits the GPL if it forms a single work, not any software with which they are merely distributed.

Rationale: This provision is aimed specifically at licenses which require an explicit gesture of assent in order to establish a contract between licensor and licensee. Provisions mandating so-called “click-wrap” may conflict with important methods of software distribution such as FTP download, CD-ROM anthologies, and web mirroring; such provisions may also hinder code re-use. Conformant licenses must allow for the possibility that (a) redistribution of the software will take place over non-Web channels that do not support click-wrapping of the download, and that (b) the covered code (or re-used portions of covered code) may run in a non-GUI environment that cannot support popup dialogues.