“Venkman” is the code name for Mozilla’s JavaScript Debugger. It can be used as an extension to Firefox. You can get it here:
http://www.mozilla.org/projects/venkman/
Here are some tutorials for Venkman:
Tag Archives: Firefox
Firebug
If you do web programming, you should get Firebug. You’re probably asking, “What is Firebug?“ Firebug is web development evolved, and it runs on Firefox!