The Safari Validator plugin lets you validate the (x)html compliance of your website from within your browser, by using the Tidy and the W3C validation engines. It uses the new Safari 5 extension mechanism.

The Safari Tidy plugin lets you validate the (x)html compliance of your website from within your browser, by using the Tidy and the W3C validation engines. This project stays online for people using older versions of Safari.

The Safari Microformats plugin informs you of specific metadata embedded in webpages by showing a badge in the URL-field of the browser. From there, you can easily add the data to Address Book or iCal.