This book constitutes the refereed proceedings of the Third European Conference on Research and Advanced Technology for Digital Libaries, ECDL'99, held in Paris, France in September 1999. The 26 revised full papers presented were carefully reviewed and selected from a total of 124 submissions. The book is divided in topical sections on image categorization and access, audio and video in digital libraries, information retrieval, user adaptation, knowledge sharing, cross language issues, case studies, and modelling, accessability and connectedness.