This book constitutes the thoroughly refereed post-conference proceedings of the Satellite Events of the 12th European Conference on the Semantic Web, ESWC 2015, held in Portoroz, Slovenia, in May/June 2015. The volume contains 12 poster and 22 demonstration papers, selected from 50 submissions, as well as 22 best workshop papers selected from 140 papers presented at the 16 workshops that took place at ESWC 2015. The papers cover various aspects of the semantic web.