4chan was founded by moot, a patron of Something Awful. Something Awful (or SA) is a website featuring a large, pay-to-register forum. A few 4chan memes (e.g. Hawaiian Punch) originate from SA, but most are either from 2chan or are original.
The anime sub-forum of the Something Awful forums. moot and a large majority of the founding 4chan team originally met here, and a few rules (such as "no furry") have been borrowed from it. There is an ongoing 4chan thread in ADTRW that is bumped every couple of weeks for apparently no reason at all.
The funniest and most exclusive subforum of The Awful Forums, frequent exchange of classic memes and awesome ideas goes on between the *chans and the 'yad.