FireBug Version .4 for Firefox!

In the new FireBug, (some) JavaScript errors include stack traces and the debugger can break on (some) JavaScript errors.  I say ‘some’ because it doesn’t seem to break on security exceptions (Venkman doesn’t either).  It feels a lot more integrated than Venkman, too!  console.debug(), console.info(), console.warn(), and console.error() let you color code your output.  And the printf-style formatting options let you embed links to dom objects in your console output.  Nice!