the domain name is in the possession of Sirius (Martti Malmi)
but it was founded by Satoshi Nakamoto in 2009 and if i am not mistaken it was hosted on sourceforge(?) and then moved to this current state you are seeing back in the days. and Theymos is the Administrator of it.
all the information is available with a simple google search

https://bitcointalk.org/index.php?topic=117354.0
https://en.bitcoin.it/wiki/BitcoinTalk
https://en.bitcoin.it/wiki/Sirius

p,s, move your topic to Meta board