For web developers, viewing the DOM and reviewing the style sheet rules are essential. With a quick command you can enable the web inspector for Safari 3.
IE developer toolbar for IE or Firebug/YSlow for Firefox — these are valuable tools for web developers and programmers. Theming, designing, and web programming without such developer tools is practically impossible.
While the other browsers require additional add-ons, Safari just requires a terminal command…
defaults write com.apple.Safari WebKitDeveloperExtras -bool true
Once you enable the flag, you will need to quit and restart safari.
Right-clicking (ctrl-clicking) on any element of the web page will show an option to open the web inspector.
The developer’s tools open which will allow for easy exploration of the style rules, properties, etc.