2chan

From SDWiki

2channel (2ちゃんねる, ni channeru?, 2ch for short) is a Japanese Internet forum, known to be the largest Internet forum in the world.It is the basis for Japanese society, featuring anime, manga, hentai, catz, ramen, cosplay, mudkipz and the like. As of 2008, the site generates revenue upwards of ¥100 million per year for creator Hiroyuki Nishimura.

It's safe to say that every *chan is a knock off of 2chan.