  The Mizar Mathematical Library (MML) is a large corpus of formalised
mathematical knowledge. It has been constructed over the course of many years
by a large number of authors and maintainers. Yet the legal status of these
efforts of the Mizar community has never been clarified. In 2010, after many
years of loose deliberations, the community decided to investigate the issue of
licensing the content of the MML, thereby clarifying and crystallizing the
status of the texts, the text's authors, and the library's long-term
maintainers. The community has settled on a copyright and license policy that
suits the peculiar features of Mizar and its community. In this paper we
discuss the copyright and license solutions. We offer our experience in the
hopes that the communities of other libraries of formalised mathematical
knowledge might take up the legal and scientific problems that we addressed for
Mizar.
