One interesting fork was egcs, forked from gcc in the 1990s, by people who wanted to try out the "bazaar" development model (as opposed to the "cathedral" model

One interesting fork was egcs, forked from gcc in the 1990s, by people who wanted to try out the "bazaar" development model (as opposed to the "cathedral" model the FSF used, which meant very little engaging of the community.) The experiment turned out very successful and eventually the egcs version was named the one and true gcc (and the gcc we use today is a derivative of it.)