I replied to your post on Muay Thai history. Some of the sites I mentioned will also have info on Krabi Krabong. Krabi Brabong (KK) was an old art that was meant to be a soldier's art not just a fighter's art (like Muay Thai). The art evolved over the years from use in the royal armies of Siam. It involves many weapons, but mostly the spear, dha and shield. My opinion is that it is a contrasting art to Muay Thai. It is based more on grace and efficient technique and less on the raw and brutal power you generally see in Muay Thai. Ajarn Chai Sirisute is often credited with bringing the art to the US mainstream during his training with Dan Inosanto in Muay Thai. That's a general description. Let me know if you have any other questions. I have done some research on the subject of KK (especially the weaponry) and have attended a couple seminars.
One of the most important people to introduce to the public the art of Krabi Krabong was Alfonso Tamez. Please reference the March 1987 issue of Inside Kung Fu for the story about his struggles bringing the art out in the US. Also Jason Webster contributed an enormous amount of effort right after him. Both are due credit as much or more so than others. Both influenced my own growth and understanding as well as many others in the US and abroad. What needs to be understood is that there are several different systems of Krabi Krabong not just one as mostly represented in the US by the Buddhai Sawan, of which is an offshoot of the Ayutthia school, of which I am a graduate. Alot of them focus on physical education, some on ceremonial performance/theatrical presentation as preservation of cultural, meditative, combative/functional usage. You will find some schools just teach various elements of each. Understanding the concept of infinity along with the basic combative principles is paramount to the core of krabi krabong if you are missing that then you are using doing a dance or physical education.
I traveled, trained with and interviewed almost every Krabi Krabong master I could find in Thailand, several of which have now passed away. Hopefully, starting next year there will be an introduction of the true various combative modalities of the system along with lerd rit(military muay thai) and the remaining authentic bare knuckle systems.
The best concise quote on Krabi Krabong comes from Jason Webster, " ..this apparent simplicity, on the surface of the art, reflects the underlying emotion inherent in it. That is the quick, economical destruction of the opponent. Bearing in mind that Krabi Krabong, and its off spring Muay Thai, evolved from Thais defending their homeland and not wonton imperialism or inter-tribal conflict. Therefore, at the core of the Thai martial arts exists the belief that if fighting must take place, the wholesale destruction of the opponent is warranted-- and in the quickest most powerful fashion....The goal being the immediate, natural response to an attack with quick, decisive strikes to incapacitate expediently."
For info on Krabi-Krabong just type Krabi-Krabong (+your country) in the GOOGLE.COM browser ("http://www.google.com"). Also you can get USA Krabi-Krabong info from "http://usmta.com/"
Jason D. Webster was a true pioneer for Krabi-Krabong here in the USA, but I have not been able to contact him at his Texas address recently.
Alfonso Tamaz was noted for being highly regarded in Dan Inosanto's JKD and Filipino Kali instructor group, but he left all that for total immersion in Muay Thai and Krabi-Krabong. Alfonso saw the "light" and went for it.
In California, USA, there are quite a few excellent Krabi-Krabong instructors.