What is better, One javascript framework, or multiple frameworks

Question

I am an avid user of the YUI framework (http://developer.yahoo.com/yui/). It has its' strengths and weaknesses both performance wise and syntax wise. I have seen a bit of JQuery and I have worked a little with prototype as well but I have stuck mainly to YUI. My question is, is it better to stick with one Javascript library per application, or leverage the abilities of multiple javascript frameworks in your application?

Answer 1

I think it is better to use one framework for at least two reasons:
1. Code is easy to maintain because there is no syntax mix.
2. Application loads a little faster and I think should execute little faster.

Answer 2

My guess is that multiple frameworks is better as long as each has its purpose. If I'm building an ASP.Net web application with AJAX functionality, there may be some built-in ASP.Net AJAX Javascript libraries being used automatically that can be combined with JQuery to handle some situations. Alternatively, one could have third-party controls like Telerik's RAD controls that also bring in more Javascript code possibly. The key is to understand what each framework is adding in terms of rolling your own.