Are there plans for a chrome js debugger?

Chromebug development appears to have stopped:

"I am not working on chromebug at present. It's too difficult to keep up
with bugs and changes in Firefox."
https://groups.google.com/group/mozilla.addons.chromebug/msg/8ab3ff38cf097656

but a platform needs a debugger, does it not?  Mozilla should either help 
Chromebug or release their own.