A thread on comp.lang.javascript discusses the speed of various JS libraries on the TaskSpeed test.
These are the results that I received on a modern Windows XP SP2 machine with dual 3.0GHz CPUs and 3.25 GB of RAM:
| Pure Dom | Dojo 1.4.0 | jQuery 1.4.0 | MooTools 1.2.4 | Prototype 1.6.0.3 | qooxdoo 0.8.2 | YUI 2.7.0 | My Library (QSA) | |
|---|---|---|---|---|---|---|---|---|
| Chrome 3.0.195.27 | 206 | 225 | 458 | 304 | 405 | 160 | 299 | 167 |
| Firefox 3.5.7 | 290 | 428 | 937 | 851 | 1105 | 406 | 866 | 447 |
| IE 8 | 906 | 2018 | 2922 | 5686 | 4529 | 1593 | 2172 | 2642 |
| Opera 9.64 | 219 | 309 | 484 | 642 | 920 | 217 | 439 | 269 |
| Safari 4.0.3 | 224 | 202 | 388 | 244 | 353 | 218 | 317 | 155 |