Presentation by Geert-Jan Janse (Teylers) & Sandra Fauconnier (Wikimedia NL) for the GLAM-Wiki conference, April 2013, British Library, UK. https://uk.wikimedia.org/wiki/GLAM-WIKI_2013 The Dutch chapter of Wikimedia and Teyler Museum organised a writing challenge from January till June 2012 to expand the coverage on various topics related to Teylers Museum and its rich collections. Curators and Wikipedians have successfully worked together, resulting in over 300 new articles in more then 13 languages, including Esperanto,Catalan and Volapük. Why did this project take place, how was it organised, what were our experiences, what are the lessons learned and how do we hope to continue our fruitful collaboration?