Book excerpt: The first dedicated new work since 1991, this book reviews recent progress and current studies in the chemistry, metabolism and spectroscopy of chlorophylls, bacteriochlorophylls and their protein complexes. Also discussed is progress on the applications of chlorophylls as photosensitizers in photodynamic therapy of cancerous tumours, and as molecular probes in biochemistry, medicine, plant physiology, ecology and geochemistry. Each section offers an introductory overview followed by concise, focused and fully-referenced chapters written by experts.