This volume is a collection of articles contributed by colleagues, collaborators and past students to honor Professor John T. Katsikadelis on the occasion of his 70 years. Professor Katsikadelis, now an emeritus professor at the National Technical University of Athens in Greece, is one of the BEM pioneers. He started his research in this field with his PhD thesis at the Polytechnic Institute of New York in the 1970s and continues it to date. The book comprises 28 contributions by more than 45 leading researchers in Boundary Element Methods (BEM) and other Mesh Reduction Methods (MRM). All contributors are well-known scientists from all over the world, Asia, Australia, Europe, North and South America. The volume is essentially a collection of both original and review articles covering a variety of research topics in the areas of solid mechanics, fluid mechanics, potential theory, composite materials, fracture mechanics, damage mechanics, plasticity, heat transfer, dynamics and vibrations and soil-structure interaction. Invaluable to scientists, engineers and other professionals interested in the latest developments of the boundary integral equation methods, the book addresses the needs of the BEM computational mechanics research community.