I'm gearing up to do some AJAX style client side Javascript in the near future and I've heard rave reviews of JQuery when it comes to this realm. What I'm wondering is:
If you've used something, please share your experiences. And do your best to avoid bringing religion into the subject.
prototype FTW
I do like JQuery, but prototype serves my needs most of the time. It may just be because I'm more familiar with it, but I seem to get stuff done faster in Prototype than in jQuery
Loads!
JQuery, Prototype, ExtJS, Dojo, Mootools, YUI, Mochikit, the list goes on!
JQuery is very popular, and an excellent choice, however some frameworks are better for some things, and others better for others. If you could give us a better idea of what you want to do, or how you will be using it (or even which other languages you use) we'd be able to give you a nudge towards one or the other.
An excellent resource is Jeff Atwood's post on javascript libraries: http://www.codinghorror.com/blog/archives/001163.html
He lists:
ALL the cross browser Javascript libraries out there? You do realize that there are well over 100 libraries out there, so you should narrow this down a little, imo.
A good place to start is with Wikipedia's Comparison of JavaScript frameworks, which covers Dojo, Ext, jQuery, midori, MochiKit, MooTools, Prototype & script.aculo.us, qooxdoo, YUI, and SweetDEV RIA.
If you want to jump on the same bandwagon everyone else does, jQuery is the end-all, be-all. You don't have to think, just listen to everyone else. :P
Personally, I use and love MochiKit. It seems to do everything jQuery does, but the philosophy is a bit different and the community is by far smaller. There are not tons of additional plugins, but there are some. It was designed with a lot of Pythonic style and functional programming constructs, so if that sounds interesting to you, you might want to take a look.
I can't think of doing any javascript development without using JQuery (also take a deep look to JQuery UI).
The list that Dori posted is pretty comprehensive, and I don't think that its possible to list all the libraries out there since there might be one being written even as I type (it seems to be a passion for some people).
I feel that going with jQuery and/or prototype will probably get you off the ground and building neat stuff pretty quickly, and chances are that you will fall in love with them as so many of us have.
Gucci had Thomas Fuchs (the creator of Scriptaculous) create their website without using Flash, but check it out, it looks amazing for being JavaScript / CSS only:
Here's a post about it:
http://ajaxian.com/archives/gucci-relaunches-on-scriptaculous
These libraries are so powerful and versatile (with some nice plugins) that you won't "hit the wall" and start looking to other libraries anytime soon.
I have also seen people do some nice stuff with Dojo and extJS, but I have never worked with them myself.
jquery is a good choice, it leans towards the 'skinny and speedy' side, and allows for some fantastic DOM manipulation.
I prefer Mootools because it is lightweight and is based on Prototype, but like Jay said you should check them out for yourself.
ot popular ones are jQuery, DojoToolkit, Prototype.js (with ScriptAculous) and MooTools. I'd encourage you to test out MooTools unless you're on ASP.NET in which case I'd encourage you to check out the project I am working on (Ra-Ajax) which is a fully server-side binded Ajax Framework for ASP.NET...