Why share alike

Compatible licenses are limited to those explicitly named. CC undertakes a detailed and participatory review process before naming any license as compatible in order to ensure that the expectations of its licensing community are being upheld.

Only licenses approved through this process are compatible; any others must be evaluated by CC and the community to ensure that fundamental incompatibilities do not exist.

You may ask CC to review a license according to the process if you believe it should be compatible. The ShareAlike term applies to licensed uses only, not uses by the rightsholder. As with all CC licenses, the SA licenses only restrict what a reuser may do under the license and not what the licensor rightsholder can do. Licensors that make their works available under an SA license are always free to share their works under other terms if they wish.

ShareAlike does not limit uses otherwise allowed by limitations and exceptions to copyright. Nothing in the SA licenses or any CC license controls or conditions uses covered by an exception or limitation to copyright or similar rights, or otherwise controls any activity for which no permission under such rights is required.

For example, in many jurisdictions, a person does not have to ShareAlike if the work as adapted is being used for purposes of criticism or parody. Similarly, because posting a link to a work does not require permission under copyright, a user may include a link to SA-licensed material on a website whose content is All Rights Reserved. In such cases, the CC license never comes into play and the SA and other conditions may be disregarded. Explanations of ShareAlike do not modify the CC license.

Some licensors or website providers state expectations or interpretations about what SA means. Those explanations never form part of the CC license , even if included in terms of service or another resource designed to contractually bind reusers.

CC strongly discourages the practice when such statements carve back rather than expand on reuses allowed by the SA definition. When those statements are intended to modify the CC license in a way that limits the permissions otherwise granted by the license, no CC trademarks may be associated with either the work or the terms under which it is offered.

Unless other restrictions are present, the work may be used for any purpose, without the need to make distinctions about allowable types of uses. You may not sublicense the Work. You must keep intact all notices that refer to this License and to the disclaimer of warranties with every copy of the Work You Distribute or Publicly Perform. When You Distribute or Publicly Perform the Work, You may not impose any effective technological measures on the Work that restrict the ability of a recipient of the Work from You to exercise the rights granted to that recipient under the terms of the License.

This Section 4 a applies to the Work as incorporated in a Collection, but this does not require the Collection apart from the Work itself to be made subject to the terms of this License. If You create a Collection, upon notice from any Licensor You must, to the extent practicable, remove from the Collection any credit as required by Section 4 c , as requested. If You create an Adaptation, upon notice from any Licensor You must, to the extent practicable, remove from the Adaptation any credit as required by Section 4 c , as requested.

You may Distribute or Publicly Perform an Adaptation only under the terms of: i this License; ii a later version of this License with the same License Elements as this License; iii a Creative Commons jurisdiction license either this or a later license version that contains the same License Elements as this License e.

If you license the Adaptation under one of the licenses mentioned in iv , you must comply with the terms of that license. This Section 4 b applies to the Adaptation as incorporated in a Collection, but this does not require the Collection apart from the Adaptation itself to be made subject to the terms of the Applicable License.

The credit required by this Section 4 c may be implemented in any reasonable manner; provided, however, that in the case of a Adaptation or Collection, at a minimum such credit will appear, if a credit for all contributing authors of the Adaptation or Collection appears, then as part of these credits and in a manner at least as prominent as the credits for the other contributing authors.

Except as otherwise agreed in writing by the Licensor or as may be otherwise permitted by applicable law, if You Reproduce, Distribute or Publicly Perform the Work either by itself or as part of any Adaptations or Collections, You must not distort, mutilate, modify or take other derogatory action in relation to the Work which would be prejudicial to the Original Author's honor or reputation.

Licensor agrees that in those jurisdictions e. Japan , in which any exercise of the right granted in Section 3 b of this License the right to make Adaptations would be deemed to be a distortion, mutilation, modification or other derogatory action prejudicial to the Original Author's honor and reputation, the Licensor will waive or not assert, as appropriate, this Section, to the fullest extent permitted by the applicable national law, to enable You to reasonably exercise Your right under Section 3 b of this License right to make Adaptations but not otherwise.

Representations, Warranties and Disclaimer. Limitation on Liability. This License and the rights granted hereunder will terminate automatically upon any breach by You of the terms of this License. Individuals or entities who have received Adaptations or Collections from You under this License, however, will not have their licenses terminated provided such individuals or entities remain in full compliance with those licenses.

Sections 1, 2, 5, 6, 7, and 8 will survive any termination of this License. Subject to the above terms and conditions, the license granted here is perpetual for the duration of the applicable copyright in the Work. Non-commercial provisions are not permitted because they fundamentally break the commons, not only through being incompatible with other licenses but because they overtly discriminate against particular types of users.

I should emphasize here that the definition is directly following the line set out in the original open source definition …. Thus, there is a meaningful distinction between attribution and share-alike requirements and other such as non-commercial NC , and it is a distinction that merits the description of share-alike licenses as being open but non-commercial licenses as not being open.

There are significant discontinuities and in particular we can meaningfully partition the set of licenses into open and not-open based on a their interoperability b the freedom they provide to all persons and companies to use, reuse and redistribute. By insisting on this meaning we are doing something valuable: creating a standard and maintaining interoperability. SA is not a step away from freedom, it is a guarantee of freedom.

The idea of a point of discontinuity and partition is a good one.