Book excerpt: Current demographic, economic and social conditions which developed countries are faced with require a paradigm change for delivering high quality and efficient health services. In that context, healthcare systems have to turn from organization-centered to process-oriented and finally towards individualized patient care, also called personal care, based on ehealth platform services. Interoperability requirements for ubiquitous personalized health services reach beyond current concepts of health information integration among professional stakeholders and related Electronic Patient Records. Future personal health platforms particularly have to maintain semantic interoperability among systems using different modalities and technologies, different knowledge representation and domain experts’ languages as well as different coding schemes and terminologies to include home care, as well as personal and mobile systems. This development is not restricted to regions or countries, but appears globally, requiring a comprehensive international collaboration. This publication within the series Studies in Health Technology and Informatics presents papers from leading international experts representing all domains involved in ehealth.