This Quintessence International (QI) annual yearbook is a compilation of selected articles representing the most significant work from the past year. Through a double-blind process that ensures anonymity and quality, our team of editors and reviewers performed the remarkable and difficult task of reviewing and evaluating many deserving submissions to present you with this outstanding selection of 20 articles. Organized by disciplines and topics, the articles provide a valuable and user-friendly resource that we hope you find enjoyable and informative.