“The Max Planck Society (http://www.mpg.de/en) and the academic publishing house De Gruyter have signed a groundbreaking agreement to cooperate in the publication of Open Access books. The agreement covers texts intended for publication by scholars at the more than 80 individual Max Planck institutes working around the world today. It encompass the full range of disciplines in which the Max Planck Society is active, including the natural sciences, social sciences, and humanities, and applies to both monographs and anthologies.”
http://lib-resc.blogspot.de/2013/01/the-max-planck-society-and-de-gruyter.html
Update: http://www.open-access-publizieren.de/blog/?p=59 (German)