This commentary summarizes the events at the recent UN Conference on Sustainable Development, commonly referred to as Rio+20, noting both the role of official national delegations and the diversity of non-state parties that were involved in a variety of venues at and around Rio+20. It sketches the background of sustainable development efforts, maps the road from the original 1992 Rio Earth Summit to the 20th anniversary gathering, and comments on the Conference’s outcomes and their implications for international law and legal institutions. In answer to the much debated question of whether the Rio+20 was a success or a failure, or something in between, the author concludes that the Conference, while disappointing to many, may have furthered the cause of sustainable development by producing a document which reflects a baseline of international norms and by fostering the increasingly important role of civil society action, commitments and partnerships, and of transnational governance.