There are some powerful tools available to the web developer to validate sites. Web Developer for Firefox is a tool that does much more than validate. It allows us to view CSS, outline selected elements, and validate in several different areas right at the W3C. In addition, the designer can instantly resize a browser window to 600×800 pixels to see how the site will appear in that resolution, and many more things.  Another tool, Silktide, allows for validation and much more. How does your site turn up on Google? Do you need to do more work with Search Engine Optimization? How well is your site written? How popular is your site? All of these and more that Silktide tests for are crucial for the business, campaign, and personal site.