Kodokan Judo is the judo that we know as it is today. It has been an Olympic sport since 1964 and is practiced in over 200 countries worldwide. It was started by Jigoro Kano in 1882 in Tokyo, Japan as a way to perfect the mind and body. Central to Kano's vision for judo were the principles of seiryoku zen'yō (maximum efficiency, minimum effort) and jita kyōei (mutual welfare and benefit). Kano rejected techniques that did not conform to these principles, and emphasized the importance of efficiency in the execution of techniques.
The ability to access judo as a fan has absolutely exploded in the last ten years. The IJF (International Judo Federation) has created a trackable world ranking list (WRL), a website to watch major tournaments free of charge (Ippon.tv), the creation of the World Judo Tour and continues to promote judo world wide. It is a great time to be a student of judo or even just a fan.