Software practice · 2007
The Open Source Definition
Open Source Initiative · Version 1.9 · 22 March 2007
- Source
- opensource.org
- Retrieved
- 27 September 2026
- License
- CC BY 4.0
- Rights holder
- Open Source Initiative
- Language
- English
The content on this website, of which Opensource.org is the author, is licensed under a Creative Commons Attribution 4.0 International License.
About this edition and its rights
Edition
The page of opensource.org, “Page created on July 7, 2006 | Last modified on February 16, 2024”, which holds version 1.9 of the definition, “last modified, 2007-03-22”. The title of the page is the title of the poster and the version and its date, from the end of the page, are also in the kicker; the dates of the page itself are left out. Links are set as plain text, the rule of the page before its closing lines is kept, and the closing lines stay in italics as on the page. Nothing else is left out.
Rights
License notice: “The content on this website, of which Opensource.org is the author, is licensed under a Creative Commons Attribution 4.0 International License.”
Footer of every page of https://opensource.org, including https://opensource.org/osd, linked to https://creativecommons.org/licenses/by/4.0/. Section 3(a) of CC BY 4.0 asks for the name of the creator, a notice that refers to the license with its URI, the URI of the material and an indication of any modification: the footer of the poster gives them. The page carries no copyright notice of its own.
Introduction#
Open source doesn’t just mean access to the source code. The distribution terms of open source software must comply with the following criteria:
1. Free Redistribution#
The license shall not restrict any party from selling or giving away the software as a component of an aggregate software distribution containing programs from several different sources. The license shall not require a royalty or other fee for such sale.
2. Source Code#
The program must include source code, and must allow distribution in source code as well as compiled form. Where some form of a product is not distributed with source code, there must be a well-publicized means of obtaining the source code for no more than a reasonable reproduction cost, preferably downloading via the Internet without charge. The source code must be the preferred form in which a programmer would modify the program. Deliberately obfuscated source code is not allowed. Intermediate forms such as the output of a preprocessor or translator are not allowed.
3. Derived Works#
The license must allow modifications and derived works, and must allow them to be distributed under the same terms as the license of the original software.
4. Integrity of The Author’s Source Code#
The license may restrict source-code from being distributed in modified form only if the license allows the distribution of “patch files” with the source code for the purpose of modifying the program at build time. The license must explicitly permit distribution of software built from modified source code. The license may require derived works to carry a different name or version number from the original software.
5. No Discrimination Against Persons or Groups#
The license must not discriminate against any person or group of persons.
6. No Discrimination Against Fields of Endeavor#
The license must not restrict anyone from making use of the program in a specific field of endeavor. For example, it may not restrict the program from being used in a business, or from being used for genetic research.
7. Distribution of License#
The rights attached to the program must apply to all to whom the program is redistributed without the need for execution of an additional license by those parties.
8. License Must Not Be Specific to a Product#
The rights attached to the program must not depend on the program’s being part of a particular software distribution. If the program is extracted from that distribution and used or distributed within the terms of the program’s license, all parties to whom the program is redistributed should have the same rights as those that are granted in conjunction with the original software distribution.
9. License Must Not Restrict Other Software#
The license must not place restrictions on other software that is distributed along with the licensed software. For example, the license must not insist that all other programs distributed on the same medium must be open source software.
10. License Must Be Technology-Neutral#
No provision of the license may be predicated on any individual technology or style of interface.
The Open Source Definition was originally derived from the Debian Free Software Guidelines (DFSG).
Version 1.9, last modified, 2007-03-22
Here’s the historical “Annotated OSD” from the early 2000’s.