The term knowledge is taken to include:
Software is excluded despite its obvious centrality because it is already adequately addressed by previous work.
The term work will be used to denote the item of knowledge at issue.
The term package may also be used to denote a collection of works. Of course such a package may be considered a work in itself.
The term license refers to the legal license under which the work is made available. Where no license has been made this should be interpreted as referring to the resulting default legal conditions under which the work is available.
A work is open if its manner of distribution satisfies the following conditions:
The work shall be available as a whole and at no more than a reasonable reproduction cost, preferably downloading via the Internet without charge. The work must also be available in a convenient and modifiable form.
The license shall not restrict any party from selling or giving away the work either on its own or as part of a package made from works from many different sources. The license shall not require a royalty or other fee for such sale or distribution.
The license must allow for modifications and derivative works and must allow them to be distributed under the terms of the original work. The license may impose some form of attribution and integrity requirements: see principle 5 (Attribution) and principle 6 (Integrity) below.
The work must be provided in such a form that there are no technological obstacles to the performance of the above activities. This can be achieved by the provision of the work in an open data format, i.e. one whose specification is publicly and freely available and which places no restrictions monetary or otherwise upon its use.
The license may require as a condition for redistribution and re-use the attribution of the contributors and creators to the work. If this condition is imposed it must not be onerous. For example if attribution is required a list of those requiring attribution should accompany the work.
The license may require as a condition for the work being distributed in modified form that the resulting work carry a different name or version number from the original work.
The license must not discriminate against any person or group of persons.
The license must not restrict anyone from making use of the work in a specific field of endeavor. For example, it may not restrict the work from being used in a business, or from being used for military research.
The rights attached to the work must apply to all to whom the work is redistributed without the need for execution of an additional license by those parties.
The rights attached to the work must not depend on the work being part of a particular package. If the work is extracted from that package and used or distributed within the terms of the work’s license, all parties to whom the work is redistributed should have the same rights as those that are granted in conjunction with the original package.
The license must not place restrictions on other works that are distributed along with the licensed work. For example, the license must not insist that all other works distributed on the same medium are open.