This volume is a tribute to Professor Dr Da Ruan, who passed away suddenly on July 31, 2011, aged 50. The flood of emails that spread throughout the fuzzy logic research community with the tragic news was testimony to the respect and liking felt for this remarkable man. Da was a hardworking, highly productive scientist who, during his short life, published 35 books and more than 250 research papers in highly ranked journals and conference proceedings. He established two successful conferences, FLINS and ISKE, as well as the international journal, JCIS. This book is a collection of contributions from 88 of Da's academic friends from 47 institutes, presented in 60 chapters and over 70 pictures. A Foreword by Lotfi Zadeh begins Da's story. Section 1 provides an overview of Da's funeral on August 6, 2011. Part II outlines Da’s scientific life, his education, scientific career, publications and keynote talks. Part III presents testimonials by Da's colleagues of academic activities, including guest professorships and his many visits to foreign institutes. Part IV contains thirty contributions from colleagues and friends across the world to describe their collaborative experience with Da. We hope this book will keep the memory of Da alive – great scientist, great friend, great humanitarian. He will remain in our hearts forever.