What unique features does Firebug have that are not built-in to Firefox?

Question

I just cleaned my Firefox addons and wondered:

• Which features does Firebug have that make it unique?

• Which features are available in both Fire

Answer 1

There are lots of small features that Firebug has that the built-in tools don't. Playing around with the UI, this is what comes to mind, but I'm sure there are more:

• closure inspection abilities, like the someFunction.%closureVar command line syntax
• right-click to play with any value in the command line
• single-click to edit
• highlighting elements on hover
• command line APIs, like include and getEventListeners
• ability to show UA styles
• "Add rule" from within the Style panel
• a CSS panel that is usable for minified CSS
• when an element contains only text, the HTML panel displays the text inline
• XHR logging in the Console with JSON prettification (and which doesn't open a popup)
• "Break on attribute change/subtree change/node removal" in the HTML panel
• "Break on mutate", "Break on next", "Break on property change", "Break on cookie change"
• a whole Cookies panel
• stack traces in the Console panel
• editing and pasting HTML
• free-text search within most panels
• lots of options to twiddle if you need to
• event logging

There are also, of course, subjective aspects to this. For instance, I personally like Firebug's UI and appearance more than the blackness of the devtools, and previous familiarity with a tool is always important.