I got Selenium IDE, followed this post, got to
python test_default_server.py
and it complains Firefox is not in my path:
Please
selenium("localhost", 4444, "*firefox C:\Program Files\Mozilla Firefox\firefox.exe", "http://change-this-to-the-site-you-are-testing/")
Worked in Java.
The *firefox etc are the keys for which browser to use to run the tests.
There is a long list of them at How to run Google Chrome with Selenium RC? - so you can target Firefox v2 (*firefox2), Firefox v3 (*firefox3), Google Chrome (*googlechrome) etc