The built-in web developer is definitely on-par with Firebug and Web Developer. In some ways it's even nicer. As far as plug-ins go, Safari's had them for year

The built-in web developer is definitely on-par with Firebug and Web Developer. In some ways it's even nicer. As far as plug-ins go, Safari's had them for years. Apple just doesn't support them or advertise them.