Mike B's set
squish for the web: http://www.froglogic.com/products/evaluate.php
Lisa TEST: http://www.itko.com/products/lisatest.jsp
AppPerfect Web Test: http://www.appperfect.com/products/app-test.html
Selenium: http://seleniumhq.org/
Felicia's set
Watij - http://watij.com/
TestMaker - http://www.pushtotest.com/
Sahi - http://sahi.co.in/w/
Yawet - http://www.informatrix.ch/indexYWT.html
Ed's Set
Yui Test with Selenium driver
Alex's Set
Sean's Set
Dave's Set
Tools that emulate a browser
Yawet (all OS's that support Java)
Tools that make record a user journey in browser and then let the tester modify the test
Yui Test
Selenium
Func Unit
TestMaker
Sahi