Styles of Nunchaku-Do
The most common traditional martial arts to use nunchaku are the Chinese, Chinese-Okinawan and Okinawan martial arts such as some forms of karate/kobudo, but some Eskrima systems also teach practitioners to use nunchaku. For its part, Taekwondo teaches how to use one and two nunchaku, though in Korean, they are known as Ssahng Jeol Bahngs, or sometimes Ssahng Jeol Bongs. The styles of these three arts are rather different; the traditional Okinawan arts use the sticks primarily to grip and lock, while the Filipino arts use the sticks primarily for striking, while Taekwondo teaches a little bit of both.
In the early 80s, Kevin D. Orcutt, an American police sergeant, holder of a black belt in Jukado, developed the OPN (Orcutt Police Nunchaku) system. Since then some American law enforcement agencies employ the Nunchaku as a control weapon instead of a straight baton, tonfa or side-handle baton, also adapted from from the Kobudo weapons family. This system emphasizes only a small subset of the nunchaku techniques, for speedier training.
There is now a dedicated World Nunchaku Association, based in the Netherlands, which teaches Nunchaku-Do as a contact sport. They use yellow and black plastic weight-balanced training nunchaku and protective headgear. They have their own belt colour system where one earns colour stripes on the belt instead of using fully coloured belts. The basic techniques and katas here at www.nunchaku-tutorials.com are from the system created by the world nunchaku association. The freestyle are not official WNA techniques.
There are many other different styles of Nunchaku-Do and you can find many of them in the page with links here at this site.