i want to know the alternative to jquery you people use and your reviews about that?
The common ones are
But there are lots of others.
My experience is that jQuery is probably the one that is most productive unless you're trying to do very specific things.
jquery is one of the best written libraries like it, and the api is not only fantastic, but fits in well with idiomatic javascript (i.e. very functional)
I work on a 5 year old app that has a big investment in prototype/script.aculo.us, and that combo is quite franky, crap in comparison.
I have played with mootools a bit, and I like what I have seen. I really don't have enough experience with it for a really informed opinion though.
Google Closure, YUI, and ExtJS are all fairly similar in that they are full out, everything-and-the-kitchen-sink type gui toolkit libraries. We use Closure at work, and I'm not a huge fan, due to how it seems to have been written by people who are really into C++/Java/C# type languages. Personally, I prefer functional over OO in a general way, but specifically in javascript object orientation plays to the languages weaknesses. That being said, it may be a plus for someone who comes from one of those languages and isn't that great at javascript.
Finally, there is stuff like sproutcore and cappucino that are full out app development frameworks. I don't have much experience with them, but have been extremely impressed with what I have seen from cappucino. http://280slides.com/Editor/ is hands down the most impressive web app of any kind I have seen so far. That being said, with these sorts of things the majority of your logic is going to be written in javascript (or obj-j) using their frameworks. IMO this is the way of the future in web development, but we really aren't there yet for a whole bunch of reasons.