On Syntax.fm episode 725, I mentioned how I’m often surprised by learning about something Safari did long before any other browser.
What’s the “wow, really?!” I learned today?
Safari was the first browser to ship developer tools.
Web Inspector shipped in Jan 2006, in Safari 2.
Firebug came out at the same time, also Jan 2006. It was an extension you could install in Firefox. And of course all the other browsers shipped developer tooling later. But Safari was the first browser to include it.