Hello @enchiridion,
You can certainly take over the plugin. It only exists in the WordPress plugin Subversion repository, it’s not in a git repository yet.
Over the past years from time to time I have considered to update the plugin, but I haven’t done any serious WP (or even PHP) development in that period, so I never found the need or the time for it. I have considered integrating it into another existing developer plugin with more traction – first Developer, but that seems abandoned as well, so maybe Debug Bar would be a better choice now.
So depending on whether you want to continue it as an independent plugin or as an extension to something existing (or maybe even a hybrid – independent, but if it detects the Debug Bar extend it), we can decide how to go forward with the code. I think you still need access to the WP plugin Subversion repository if you want to publish it in the plugin directory, but you could do the main development via git and then via a git->svn bridge put it there.
Let me know what you want to do, and we will figure it out. I’ll send you a mail via your site so you have my contact details.
Regards,
Jan