Registration is now open for Rio+Social, the historic meeting of social media, technology, global development and sustainability leaders during the UN’s Rio+20 conference.

Policy makers, journalists, technologists and environmentalists are now invited to register and apply for accreditation to the free conference.

Ten exciting new speakers were added to the Rio+Social lineup Wednesday, including entrepreneurs, UN leaders and philanthropists.

Former president of Ireland Mary Robinson and Bill & Melinda Gates Foundation chief communications officer Kate James are among the just-announced speakers. You can view the complete list of speakers added Wednesday on the Rio+Social website.

Rio+Social will be hosted by the founders of the annual Social Good Summit: the United Nations Foundation,Mashable and the 92nd Street Y. The conference is also made possible with generous support and innovative leadership from Ericsson, Energias de Portugal and LiveAD.