Aikido has now matured as a martial art. There are perhaps 200,000 active practitioners worldwide while several millions have had direct training experience in the art. Hundreds of books have appeared on the subject in many different languages. Most of these are of a technical nature while a few authors have adopted a philosophical approach to the art.
The Biographies and Terms section includes approximately 800 alphabetical entries in the form of capsule biographies of persons of significance in aikido and Daito-ryu Aikijujutsu, definitions of specialized terms, and short histories of aikido in 15 countries.
