The German Institute for Legal Questions on Free and Open Source Software considers the European Union's software licence EUPL to be one of the seven most important open source software licences. "It is anticipated that this license will be increasingly used by public administrations for licensing independent developments", the Ifross writes in a review, part of its Frequently Asked Questions, posted on its website in January.
The institute, a network of lawyers and legal experts mostly based in Germany, describe the EUPL as a license developed by the European Commission with a strict copyleft that exists in 22 of the languages of the EU's member states. They note that the licence is compatible with the GNU General Public Licence.
The GPL is the most important and widespread open source license, writes Ifross. "Approximately 60 per cent of all open-source software is under this license. This includes well-known programs like Linux or Busybox. The GPL is the template for all licenses with a strict copyleft."
Another licence in the top seven of for free and open source software, Ifross says, is the GNU Lesser General Public License. This was conceived especially for program libraries. The other four licences on the think tank's list are the Apache Licence, the BSD licence, the Common Public License and the Mozilla Public License.
The EUPL is on its way to add the GPLv3 to its list of compatible open source licences. At the EC's Joinup project website, a public consultation for the revision of the EUPL was announced in December. Suggestions for improvements are welcome until the end of this week. Several additional changes have been proposed already. In January, for instance, one of the users of Joinup suggested to include also the Cc-by-sa to the list of compatible licences. This could help public administrations that want to publish software code along with its documentation and logos.
The new update of the EUPL, version 1.2, is planned for publication in June 2013.
Ifross licence review (in German)
Ifross licence review
EUPL consultation website
Rationale for the evolution of the EUPL (pdf)
Blog post by Bristol Wireless