The library I hear the most about is jQuery. However there are a whole lot more. Developers sometimes think that ExtJS does not get enough press.
If you are not integrating it into a commercial product, you can get ExtJS for free. You add some lines of code to your header section to bring in the ExtJS functionality. Then you use the extension library framework.
Be Brave to Get Work Done - I was woken up this morning from a call from work. Not a good sign. Apparently the customer found a potential problem in our delivery. I got on a conferen...