Book excerpt: Gear Cutting Tools: Fundamentals of Design and Computation, Second Edition, presents the DG/K-based method of surface generation, a practical mathematical method for designing gear cutting tools with optimal parameters. The text addresss gear cutting tool evolution, and proceeds to scientific classification for all types of gear machining meshes before discussing optimal cutting tool designs. Designs currently used and those being planned are covered, and the approach allows for development of scientific predictions and optimal designs. Solutions appear in analytical form and/or graphical form, with a wealth of new figures added, and new appendices offer additional data for readers.