Licences ensure that communities behind many of today’s most innovative technologies can protect their creations in whatever way they see fit. The open source licence determines how openness is defined from a legal perspective. Depending on whether one wants to license a small software tool, a larger framework, datasets or an internet service, the choice of licence can determine the long-term strategic direction. In this way restrictions, conditions and guarantees are defined by the authors under which use and derivations are possible. Especially for commercial use, licensing criteria play an important role. Websites like ChooseALicense can help you choose the right licence. The distribution of licences reveals the orientation of the open source ecosystem towards more permissive licences or copyleft licences.