Maarten Claus is the artistic director of Klein Haarlem, a non-profit organisation focused on cultural events, work and social dynamics. Their biggest event is Boring Festival, a two-day multi disciplinary event in cooperation with museums, pop and theater venues. Klein Haarlem also runs a creative hub in a big historic building in the center of Haarlem called De Greiner. Other work includes working with men on transforming genderroles with his group Mannen+, being part of the team of Haarlem Breekte De Stilte and being a volunteer for Emancipator.