I'm often disappointed that Venkman is implemented as an in-process debugger. Doing so requires manipulating the main thread's event queue when you're paused (so that Venkman itself responds), allowing new event handlers to fire and generally mucking up complicated situations. For debugging simple web pages, Firebug has the same problems but a cleaner interface and fewer bugs. For heavier XUL development, Venkman is the option option, but I would much prefer an out of process debugger capable of debugging threads (which I think is a js/jsd limitation).
For small stuff I'll just use Firebug, but for the heavy lifting it's still Venkman for me. You can debug chrome with it, set breakpoints, read the stack, set it to trigger on errors or exceptions, etc.
Has anyone here used this in anger? I'd be interested to know if it works better than, say, Firebug? The latter tends to have problems with dynamically loaded iframes (like those used with Google Gadgets), and will often miss breakpoints in event handlers. If Venkman were better in this respect, that'd be fantastic.
Chromebug is Firebug for XUL applications and extensions. <a href="http://getfirebug.com/extensions/index.html#chromebug" rel="nofollow">http://getfirebug.com/extensions/index.html#chromebug</a>
IE8 has not a bad js debugger. At least it is stopping for me on breakpoints and is more stable than firebug. In Beta it was crashing/hanging, but it seams they improved something.