What are the alternatives to the Firefox Developer Tools?

Question

Since last few updates of Firefox our beloved Firebug is integrated into the Firefox Developer Tools and a lot of people including me don\'t like what happened to Firebug.

Answer 1

Or can find other similar plugin. So far I find the Plugin 'Xpather' in http://xpath.alephzarro.com/ link. But I still would like to reactivate Firebug to rework by setting the preferences browser.tabs.remote.autostart, browser.tabs.remote.autostart.1 and browser.tabs.remote.autostart.2 to false via about:config.