This book represents the first complete and systematic guide to the virus-like particles (VLPs) and their applications as vaccines, therapeutic tools, nanomaterials, and nanodevices. The grouping of the VLPs follows the most recent virus taxonomy and the traditional Baltimore classification of viruses, which are based on the genome structure and mechanism of mRNA synthesis. Within each of the seven Baltimore classes, the order taxon serves as a framework of the chapter’s arrangement. The term "VLP" is used as a universal designation for the virus-, core-, or capsid-like structures, which became an important part of the modern molecular virology. The 3D structures, expression systems, and nanotechnological applications are described for VLPs in the context of the original viruses and uncover their evolving potential as novel vaccines and medical interventions.