Awesome post, thanks Martin!
Thank you. Just for that bit of praise, here are a few more.
Daido juku was founded in 1981 by Azuma Takashi. Takashi was asked to develope new more realistic rules for kyokushin, but when his new "kudo" rules was ready, Oyama thought than knockdown had spread too much and could not be replaced. So Takashi requested and received permission to leave and found a new style (making it one of few friendly splits in kyokushin history) to use the rules.
Daido juku kudo is a mix of kyokushin and judo -with more recent muaythai and BJJ influences. Daido juku competitions are closer to MMA in feel, but the knockdown karate roots are obvious -look them up at youtube.
Daido juku guys going pro tend to compete in pancrase.
Seiwakai karate was founded by the famous brazilian kyokushin fighter Ademir DaCosta in the late 90ies (im to lazy to check). Apart from fighting trad knockdown karate internally, they are heavily involved in Brazilian MMA and Chute Boxe -with great success as I hear.
Sato juku (actually that is the name of the Org. the style is called Odo karate). Created by the first kyokushin world champion Katsuaki Sato. Their version of knockdown allows for 2 points rewarded for technically perfect techniques that DO NOT contact (while still allowing 1 point for a temporary stun and 3 points/win for knockdown/knockout) -to encourage more technique and less "slugging".
Kyokushin budo kai was founded by Jon Bluming, who was expelled from kyokushin in the late 60ies. He was also a high ranking judoka, and his style is a mix of the two. Basically you start with knockdown karate standup, but allows takedowns/throws and judo newaza.
Byakuren is a offshot from Shorinji kempo. The founder was expelled from shorinji after he entered kyokushin tournaments to test his skills. It is basically shorinji kempo heavily adapted to traditional knockdown competition rules.
While the basics are not from kyokushin, the fighting looks identical and the rules are identical to trad kyokushin knockdown rules.
They work closely with the shinkyokushin faction of kyokushin (which I belong to) and often compete in shinkyokushin tournaments.
Tsu Shin Gen was founded by David Cook (born in the US, living in sweden). He started out in kyokushin, continued in ashihara and has now founded TSG, which is a happy mix of karate, kickboxing and MMA. It is large in eastern europe.
Zendokai is a recent offshot from Daido juku created by Takashi Ozawa in 1999. Basically it is MMA karate. They are involved in a lot of japanese MMA events.
this Zendokai so far exist only in japan and some eastern asian countries. Do
NOT confuse it with the australian Zendokai created by Bob Jones -there is no relation and few similarities.
Wajutsu Keishukai is a offshot from daido juku created 1987 with strong judo influences. Although more of a chain of MMA gyms (and one of the most successful MMA gym chains in japan) and not karate nowdays.
Koi karate is a bunch of crazy russians. Originally founded by a kyokushin trained army close combat specialist (who also trained in knife fighting techniques which is now taught in the style) they now fights basically no rules bareknuckle MMA. As part of their grading they have to place (at least 3rd place) in full contact martial art events of other organzations. The higher the grade, the higher the level the tournament.
There are so many more. Some are descended from kyokushin, others are just influenced by it but is not actually related.
Shurenkan, Mumonkai, Toshinkai, Shinaido, Shinbukan, Kenshinkan, World Miura Karate, Gyakushin. The list goes on and on and never seem to end.
Ranging from decent sized international organizations to a mere handful of dojos.
Then there are pure competition organizations like shinkarate (literally "new karate"). A japanese umbrella organization for karate dojos fighting "gloved karate" (a popular amateur sport that is growing fast in japan). Basically a variation of kyokushin knockdown but with boxing gloves and headpunches.
Shinkarate has been a major source of new japanese k-1 fighters recently. Junichi Sawayashiki (who lost big to Peter Aerts in the first round of the 2007 K-1 final) being the most well known.
but Shinkarate is not a style organization, and there are many small independent dojos -each with its own style, attatched to it (most are formerly kyokushin or related, but many are from other lineages entirely).
Shinkarate calls their tournaments (all amateur -there is no pro league. Gloved karate guys going Pro do kickboxing) K-2 to K-5 (yes they have bought the rights to the names from k-1). K2 is the full rules using only boxing gloves. K-3 is the "suited up" version with chest protector, helmet and shin guard. K-4 is youth rules with lighter contact and Helmet (no chest protector or shinguard) and k-5 is the young children version (marshmallow-man protection, lower contact).
There are a few other gloved-karate organizations, but shinkarate is by far the largest.
Then you got the traditional full contact forms of karate.
Irikumi is the traditional fighting from Goju ryu karate from before the days of no/light contact point karate.
Now sadly all but forgotten in most of Goju ryu, Irikumi is continuous fighting using gloves -either full contact or semi contact depending on the purpose of the sparring (test of skill or test of toughness). Very similar to shinkarate K-2 rules. Irikumi was actually what Oyama, the founder of kyokushin did when he was a goju ryu man under the japanese goju ryu legend Gogen Yamagushi.
Bogu kumite is the traditional Okinawan form of fighting used in different variations in many styles.
Basically it is full contact but using a lot of padding (somewhat similar to shinkarate k-3 rules).
Originally they used Kendo armor and helmets, but nowdays they thankfully have more suitable protection.
Usually it is continuous fighting, but some styles stop after each hit to hand out points like in point karate.
Im not going into "american full contact karate". Partly because there are so many different kinds and I dont really know much about them, and partially because I have been less than impressed by what Ive seen of it.
Old dates are old dates, no can be expected to rememeber them all.
