If you have this problem, how do you solve it? Do you use a framework like YUI? Something else?
What in your opinion is a must-have for such a framework?
For example, imagine a user profile page on a social network.
The page might come preloaded with a Javascript widgets that you use all over your site, like a common interface element to hide and expand content. These widgets might demand some base Javascript libraries, as well as their own CSS classes and images.
Then, if the user wants to edit their hometown, we might want to load a map widget. Since this is a rare thing, we didn't include it in the page, but we decided to load it on demand. Once again we might load a lot of base JS, CSS or images.
Now, obviously this is all possible by inserting each dependency manually. But when your site gets really big and dependencies get very complicated, one wants to be able to say to a framework "hey, framework, go make sure this page has everything it needs for hide/expand widgets". Or, "hey framework, the user just clicked 'edit hometown', so now we need everything required for map widgets".