A relatively recent global movement, the development of free-to-use open educational resources (OER) has generated a dynamic field of widespread interest and study regarding methods for creating and sustaining OER. To help foster a thriving OER movement with potential for knowledge-sharing across program, organizational and national boundaries, the Institute for Knowledge Management in Education (ISKME), developed and conducted case study research programs in collaboration with six OER projects from around the world. Embodying a range of challenges and opportunities among a diverse set of OER projects, the case studies intended to track, analyze and share key developments in the creation, use and reuse of OER. The specific cases include: CurriculumNet, Curriki, Free High School Science Texts (FHSST), Training Commons, Stanford Encyclopedia of Philosophy (SEP), and Teachers' Domain.