Apple has updated the Safari Web Inspector. In this release it appears to have caught up with Firebug, and is actually surpassing it in some areas with features like selector-based search in the Elements view and a timeline-based network monitor with latency display.

firebug safari webkit

John Resig blogs about the new Firebug release:

The Script panel (the JavaScript debugger), the Net panel (network monitoring), and Console panel have all seen considerable updates. They're all much more performant and have a huge number of bug fixes.

Firebug changes the way you develop for the web. You won't be able to go back to alert() and background-color: red after you spend some time with it.

firebug firefox guru javascript