Mr. Bartle's writing is precise and his facts carefully researched, even the ones he experienced himself. This is a huge, superbly constructed history of the tools and philosophies developed over the years in experimental and commercial development of online virtual worlds. Because of Mr. Bartle's personal knowledge as a long-time designer and his sharp memory for the significance of trends and details, this book will raise anyone's appreciation of whatever virtual worlds one comes across on line or on disk, whether they be famous commercial ones or those developed by enthusiasts for their own pleasure. I would think it would be a must read for gaming students. What a grand, satisfying, fascinating book! And when one considers that this exciting history is only the beginning of VW development... Wow!