Umm, Mongrel2 is probably great, but it certainly doesn't have wide adoption as of yet. It was started only a few weeks ago. You may be thinking of the original

Umm, Mongrel2 is probably great, but it certainly doesn't have wide adoption as of yet. It was started only a few weeks ago. You may be thinking of the original Mongrel, which doesn't really have any relation to the new one except by name. (And they're both http servers.)