Version 2.1
The Open Definition makes precise the meaning of “open” with respect to knowledge, promoting a robust commons in which anyone may participate, and interoperability is maximized.
Summary:Knowledge is open if anyone is free to access, use, modify, and share it — subject, at most, to measures that preserve provenance and openness.
This essential meaning matches that of “open” with respect to software as in theOpen Source Definition and is synonymous with “free” or “libre” as in theFree Software Definition andDefinition of Free Cultural Works.
The termwork will be used to denote the item or piece of knowledge being transferred.
The termlicense refers to the legal conditions under which the work is provided.
The termpublic domain denotes the absence of copyright and similarrestrictions, whether by default or waiver of all such conditions.
The key words “must”, “must not”, “should”, and “may”in this document are to be interpreted as described inRFC2119.
An openworkmust satisfy the following requirements in its distribution:
Theworkmust be in thepublic domain or provided under an openlicense (as defined in Section 2). Any additional terms accompanyingthe work (such as a terms of use, or patents held by the licensor)must not contradict the work’s public domain status or terms of the license.
Theworkmust be provided as a whole and at no more than a reasonable one-time reproduction cost, andshould be downloadable via the Internet without charge.Any additional information necessary for license compliance (such as names of contributors required for compliance with attribution requirements)must also accompany the work.
Theworkmust be provided in a form readily processable by a computer and where the individual elements of the work can be easily accessed and modified.
Theworkmust be provided in an open format. An open format isone which places no restrictions, monetary or otherwise, upon its use and can be fully processedwith at least one free/libre/open-source software tool.
Alicenseshould be compatible with other open licenses.
Alicense is open if its terms satisfy the following conditions:
Thelicensemust irrevocably permit (or allow) the following:
Thelicensemust allow free use of the licensed work.
Thelicensemust allow redistribution of the licensed work, including sale, whether on its own or as part of a collection made from works from different sources.
Thelicensemust allow the creation of derivatives of the licensed work and allow the distribution of such derivatives under the sameterms of the original licensed work.
Thelicensemust allow any part of the workto be freely used, distributed, or modified separately from any other part of the work or from any collection of works in which it was originally distributed. All parties who receive any distribution of any part ofa work within the terms of the original licenseshould have the same rightsas those that are granted in conjunction with the original work.
Thelicensemust allow the licensed work to be distributed along with other distinct works without placing restrictions on these other works.
Thelicensemust not discriminate against any person or group.
The rights attached to the workmust apply to all to whom it is redistributed without the need to agree to any additional legal terms.
Thelicensemust allow use, redistribution, modification, and compilation for any purpose. The licensemust not restrict anyonefrom making use of the work in a specific field of endeavor.
Thelicensemust not impose any fee arrangement, royalty, or othercompensation or monetary remuneration as part of its conditions.
Thelicensemust not limit, make uncertain, or otherwise diminish the permissions required in Section 2.1 except by the following allowable conditions:
Thelicensemay require distributions of the work to include attributionof contributors, rights holders, sponsors, and creators as long asany such prescriptions are not onerous.
Thelicensemay require that modified versions of a licensed workcarry a different name or version number from the original work or otherwise indicate what changes have been made.
Thelicensemay require distributions of the work to remainunder the same license or a similar license.
Thelicensemay require retention of copyright notices and identification of the license.
Thelicensemay require that anyone distributing the work provide recipients with access to the preferred form for making modifications.
Thelicensemay require that distributions of the work remain free of any technical measures that would restrict the exercise of otherwise allowed rights.
Thelicensemay require modifiers to grant the public additional permissions (for example, patent licenses) as required for exercise of the rights allowed by the license. The license may also condition permissions on not aggressing against licensees with respect to exercising any allowed right (again, for example, patent litigation).
The Open Definition was initially derived from the Open Source Definition, which in turn was derived from the original Debian Free Software Guidelines, and the Debian Social Contract of which they are a part, which were created by Bruce Perens and the Debian Developers. Bruce later used the same text in creating the Open Source Definition. This definition is substantially derivative of those documents and retains their essential principles. Richard Stallman was the first to push the ideals of software freedom which we continue.