Firefox's developer tools are really becoming great. "Copy as CURL" for the network tab was something in chrome that I really missed. Box model view which was super handy is now editable. Console showing stack traces along errors was long due. New Canvas debugger, eyedropper are very handy.
Font viewer, responsive design tools, the 3d view (very handy in debugging silly box model issues) and highlight painted area mode (handy in optimizing visualizations) are all things I love that I haven't been able to find good analogues for in other browsers.
Font viewer, responsive design tools, the 3d view (very handy in debugging silly box model issues) and highlight painted area mode (handy in optimizing visualizations) are all things I love that I haven't been able to find good analogues for in other browsers.