jQuery is pretty great, but YUI shines in bigger projects for larger teams. The 1) module system, 2) conditional loading 3) combo loading and 4) and bias for st

jQuery is pretty great, but YUI shines in bigger projects for larger teams. The 1) module system, 2) conditional loading 3) combo loading and 4) and bias for structuring your code with pub/sub; these really really help in cases where there might be many javascript mini-apps running on the page who can't know anything about the other. jQuery has these things too, especially recently, but YUI enforces this... for better or worse, in a more "enterprise-y" way