Prototype alters stuff but jQuery doesn't. So there is very little conflict. The use of Prototype however will prevent use of other altering js frameworks like

Prototype alters stuff but jQuery doesn't. So there is very little conflict. The use of Prototype however will prevent use of other altering js frameworks like MooTools. Fundamentally I think Prototype/MooTools are horribly designed javascript library because they introduce incompatibilities. However I use them when I need a free component or 2. I would never drop jQuery though so I always use $j instead of $, even when using jquery by itself