This book constitutes the thoroughly refereed post-conference proceedings of the International Workshop on Interoperability and Open-Source Solutions for the Internet of Things, FP7 OpenIot Project, held in Conjunction with SoftCOM 2014, in Split, Croatia, in September 2014. The 11 revised full papers presented together with the extended abstracts of 2 keynote talks were carefully reviewed and selected from numerous submissions during two rounds of reviewing and improvement. The papers are organized in topical sections on OpenIoT platform, open platforms and standards, and IoT Applications.