This book introduces electronic institutions (EIs) and illustrates three real-life applications that focus on mixed human-software agent communities: uHelp, users find help within their social network for their day-to-day activities; WeCurate, museum visitors collaboratively browse and curate an art gallery; and PeerLearn, a platform where teachers can set up online classes that follow their lesson plans. The book also presents the PeerFlow system, a system designed and built for peer-to-peer electronic institutions which provides an intuitive user interface allowing nontechnical users to specify and share institutions. The book features contributions from leading researchers in the area of agent technologies and artificial intelligence, and it will be useful for postgraduates, researchers, and practitioners in this domain.