Sunjang Baduk is one of the forms of Go, which was common in Korea through the 16th century.
The opening leads straight into a fierce middlegame. Perhaps this is why the character of Korean players is the way it is. The other main difference lies in the way of scoring. After all plays have been made, as many internal stones as possible are removed, leaving continuous boundaries. Then the totals of territory controlled are counted, with prisoners ignored. (source: the Hankuk Kiwon Guidebook)
There are more detailed information about Sunjang Baduk at : http://www.gogod.co.uk/NewInGo/Sunjang_1.htm
S_Cho: There are a few examples of Sunjang baduk (up to first 200 movements) online, originated from a go megazine published in 1934.
Bill: People have long debated the merits of area scoring (ChineseScoring) vs. territory scoring (JapaneseScoring). (See TerritoryAndAreaScoring.) In my humble opinion, Korean scoring combines the advantages of both. Its only drawback is unfamiliarity.
EverCat: I wholeheartedly disagree - one of the joys of both Japanese and Chinese scoring is that the player who "controls" the majority of the board is (almost) always the winner "on the board" (ie before komi). I think that's beautifully logical, but it's not necessarily true here, is it?
Bill: Well, it's still about controlling, with more emphasis on surrounding. I don't see that it's any less logical.
Evercat: I think it's highly illogical. In essence, it says some stones on the board will be counted as territory, while others won't, depending on their location. Really odd, in my opinion.
Bill: The only stones that count are the ones that form the boundaries, and you don't count them. ;-)
Ellbur: This scoring system is highly unnatural: cutting points allowed, atari not allowed, some stones removed, some not.
iopq: The Japanese scoring system is highly unnatural: you can't play out life and death, your own men hurt your score, there are sometimes arguments if you have to reinforce or not, bent four in the corner is dead due to the way life and death is played out (no ko threats in the life and death stage of the game by Japanese rules)
Warp: You can play, the game position is just restored after the play. Ok, not the best possible solution, but from the thousands of games I have played I don't remember even one single example where this had caused a problem. As for reinforcement, if your opponent refuses to reinforce then you just play there and capture; what's the problem? And as for the bent4-in-the-corner, it is usually dead in all rulesets (barring some rare exceptions) (saying that the bent4 situation has to be played out in other rulesets is simply wrong: The rulesets do not force anyone; if the corner group is dead and both players agree then it would be a complete waste of everyone's time to have to explicitly play it out.)
Leira: I have found this other placement in some places (including Wikipedia in Korean). Can any of you confirm whether or not this is completely bogus (I can't read Korean, sorry about that)?