it uses Javascript. Hover over the name of the color and the background of the page changes to that color. On the same page there are examples of text using all the colors mentioned so you can see how each color looks on every background.
Semantic data extractor: This tool, geared by an XSLT stylesheet, tries to extract some information from a HTML semantic rich document. It only uses informations available through a good usage of the semantics defined in HTML.
Javascript
Webdeveloper.com.
Meta tags
Meta Medic: checks meta tags for validity and offers some suggestions for improvement.
