Libraries are spaces for learning, discovery, and also for interaction. Their architecture is currently the subject of much discussion, as the demands on these cornerstones of modern civilization have changed enormously since they have had to meet the requirements of the new multimedia and digital age. The library as an institution underwent a real image change from an introverted knowledge repository to a globally networked information provider and communication mediator. The architectural expression of this expanded and constantly evolving profile of requirements makes library construction extremely multi-layered and complex. But this is also precisely the source of enormous potential for bold designs and ingenious aesthetic concepts. Whether involving new buildings, conversions or extensions, this volume shows the diversity of this building task with its interplay of state-of-the-art technology and cultural demands.