How many projects are licensed under the EUPL? – more than 15 000 !
It looked difficult to answer this question, because of the lack of efficient search tools. Searching the word “EUPL” on search engines like GOOGLE returns little relevance, since “EUPL” has other meanings (for example “European Union Prize for Literature”). Searching the more relevant string “licensed under the EUPL” is certainly better, providing about 30,000 results, but it still produces a lot of documentary noise since it is necessary to separate anecdotic mentions or simple content (in articles, guidelines, web site pages etc.) from code files “licensed under the EUPL”. It is also necessary to search in various languages, and not only in English. Furthermore, a single project may include many files, each of them repeating the wording “licensed under the EUPL”.
It looks more efficient to focus the search into specific "code databases” like the one implemented by Black Duck. Open Hub is a free code search engine and data base indexing over 21,000,000,000 lines of open source code. At the end of 2015, searching EUPL in Open Hub provided more than 9,000 results. Results inspection has demonstrated good relevance (no documentary noise: each file is effectively licensed under the EUPL). However several files belong to the same project and with an average of 4.5 licensed files per project, the real number of projects covered by the EUPL in Open Hub looks to be about 2,000 (at the end of 2015). In fact, much more projects covered by the EUPL exist, knowing that many projects are not or not yet indexed in Open Hub.
According to the estimation from Github, there are about 15,000 project licensed under the EUPL, while the licence was not yet proposed by Github in its "chosealicense" support tool. As it was commented by Github users, those 15,000 projects made the decision to use the EUPL despite it was not offered as a choice by Github.
The discussion concluded (on 19. January 2016) on the insertion of the EUPL in the Github proposed licences
A significant finding is that most of the reported projects are not copyrighted by the European Commission, but by developers and enterprises from various European Member States.
URL of the Open Hub search engine:
http://code.openhub.net/search?s=EUPL%20&pp=0&ff=1&mp=1&ml=1&me=1&md=1&filterChecked=true
URL of the Github discussion:
https://github.com/github/choosealicense.com/issues/229#issuecomment-172662463