This document provides an overview of the investigation done by the Succeed project in the context of content, data/metadata and tools licensing. Table below provides a summary of the licenses that were investigated. It provides information on the applicability of the investigated licenses with additional explanation comments if necessary. There is a distinction between content (original creative material for human consumption), data/metadata (collection of information), and software (original creative material for computational use).
|License||Domain of aplication||Comments|
|Creative Commons CCZero (CC0)||Content, Data||Dedicate to the Public Domain (all rights waived)|
|Open Data Commons Public Domain Dedication and Licence (PDDL)||Data||Dedicate to the Public Domain (all rights waived)|
|Creative Commons Attribution 4.0 (CC-BY-4.0)||Content, Data|
|Creative Commons Attribution (CC-BY)||Content||All versions 1.0-3.0, including jurisdiction “ports”|
|Open Data Commons Attribution License (ODC-BY)||Data||Attribution for data(bases)|
|Creative Commons Attribution Share-Alike 4.0 (CC-BY-SA-4.0)||Content, Data|
|Creative Commons Attribution Share-Alike (CC-BY-SA)||Content||All versions 2.0-3.0, including jurisdiction “ports”; version 1.0 is little used and not recommended because it is incompatible with future versions|
|Open Data Commons Open Database License (ODbL)||Data||Attribution-ShareAlike for data(bases)|
|Apache License v.2.0||Software||See section 5.6 Licenses compatibility/proliferation of the full licensing recommendations report.|
|BSD license||Software||See section 5.6 Licenses compatibility/proliferation of the full licensing recommendations report.|
|GNU General Public License v3.0 (GPL)||Software||See section 5.6 Licenses compatibility/proliferation of the full licensing recommendations report.|
|GNU Library or “Lesser” General Public License v.3.0 (LGPL)||Software||See section 5.6 Licenses compatibility/proliferation of the full licensing recommendations report.|
|MIT license||Software||See section 5.6 Licenses compatibility/proliferation of the full licensing recommendations report.|
|Mozilla Public License 2.0 (MPL)||Software||See section 5.6 Licenses compatibility/proliferation of the full licensing recommendations report.|
|Common Development and Distribution License||Software||See section 5.6 Licenses compatibility/proliferation of the full licensing recommendations report.|
|Eclipse Public License v.1.0||Software||See section 5.6 Licenses compatibility/proliferation of the full licensing recommendations report.|
In the full report we have reported on existing frameworks for licensing content, data and tools. We have not been able to find a framework that covers all types of resources satisfactory. In general, license developers like Creative Commons advice not to apply their licenses to other resource types than those they were developed for1.
In order to facilitate the adoption of tools and reuse of data, we recommend adhering to the practice of using separate frameworks for data and software.
Also here, we will make a distinction between recommendations for licensing content, data/metadata and software. Some general considerations are useful for all types.
1. Check whether any rights are resting on the resources underlying the product. Sublicensing is only possible if the original license of the resources allows it. If sublicensing is allowed, the original licenses might impose restrictions on the type of license for (re-) distribution.
2. If the underlying resources are free of rights (see Chapter 2 of the full report for more information), it is not possible to license the product, unless the product qualifies as a derivative work. It that case, it is only possible to license the additional part of the product.
Content should be provided with an explicit licence so that licensees know what they can do with it. Furthermore we recommend using popular licensing frameworks to allow maximum interoperability. The results of the survey presented in Chapter 6 of the full report show that Creative Commons was used most by the respondents. This is even more evident when considering answers to the survey question related to the most important characteristics for content licensing framework. Respondents indicated mostly attribution, non-commercial use and non-derivative works. This kind of distinction can be provided by the Creative Commons (e.g. CC BY-NC-ND license).
Data and metadata should be made as open as possible in order to optimise discovery of the content curated at responsible institutions. We recommend using the Open Data Commons licenses or the Creative Commons 4.0 licenses. Since attribution is a strong requirement according to the results presented in Chapter 6 of the full report, we specifically recommend the Open Data Commons Attribution License (ODC-By), or the CC (4.0) BY License to be used in this case. For metadata that is related to objects published online in digital libraries (that can be harvested by external parties) we recommend Europeana Licensing Framework. Such an approach will make it possible to add metadata to the Europeana portal and brings the information about digital objects to any interested party. In practice using the Europeana Licensing Framework means that metadata is released under Creative Commons Zero Public Domain Dedication license (CC0).
In general we recommend a strong copyleft license for non-commercial software. Since there are many FLOSS licenses available for software tools it is difficult to decide which particular license to use. Nevertheless, there is a tendency towards a restricted set of licenses used by software developers. In Chapter 5 of the full report we have shown that among FLOSS licenses only several licenses are popular and just a few of them are widely used in the context of digitisation tools. Based on that we recommend the following set of licenses to be considered when releasing software:
- GNU General Public License v.3.0. This is the primary license to be considered when releasing a software tool. It assures that your work and any derivative work will be available in the same manner. It is especially recommended for tools that provide unique functionality – meaning that it does something no other already existing tool can do. In such a case the software tool can be of high interest to other parties and when they use or modify it they are obliged to release the derivative work under the same license.
- GNU Library or Lesser General Public License v.3.0. This license should be considered when special circumstances appear, e.g. when our tool provides functionality that is already available in other tools licensed with a more permissive license than GPL. In such case making the software GPL licensed will limit the number of users (proprietary tools will not use our tool and will favour other solutions instead – this may happen even if the quality or readiness of our software is better).
- Apache License v.2.0. This license is most permissive and it should be used in cases where a software tool should be fully available to the user community, including use in commercial products. Sometimes commercial companies use this license to make the FLOSS tool flexible for use in proprietary solutions. An example can be Android OS, which is licensed under Apache License v.2.0. Thanks to that it is possible for smartphone vendors to create special editions of Android that are not publicly available (the source code is not published).