Despite standard open licenses created by CC and Open Knowledge International (via the Open Definition), many organizations develop their own ‘open’ licenses. This poses challenges for users, because they can’t be sure that these are truly open, preventing us from moving towards a legally compatible data commons. This workshop is to discuss open licensing and how we can make progress so that the promise of being able to combine and share freely can be accomplished. We hope this will result in a renewed effort between Creative Commons and Open Knowledge to tackle open license proliferation.