Paessler Site Inspector 4.1 Freeware Edition
"Site Inspector is a Web browser that combines the two most frequently used browser engines (Internet Explorer and Mozilla/Gecko) into one program. Its advanced web page analysis features make it the perfect companion for webmasters and web developers.
Whenever you access a web page using Internet Explorer, Firefox, or Site Inspector's browser you will find a wealth of analysis functions in the toolbars and menus. For example:
For any given URL, users can access lists of the images, forms, links, frames, metatags, or the scripts of a web page as well as the HTML source and HTTP headers.
Using the Highlight function, users can mark any HTML tag with a colored border inside the rendered web page (e.g., to show all TD tags in a page). An invaluable tool for web designers.
A pixel grid as well as guide lines can be shown in a web page.
All image tags and link URLs can be shown right inside a web page.
You can copy the page URL, page title, page source, list of URLs, and even the page as a bitmap to the clipboard.
The browser window can be resized to various standard screen sizes (e.g. 800x600) and you can zoom into a web page.
A fine selection of tools that are available online (e.g. "CSS/HTML validation", "link checking", "ping the server", "traceroute the server", "show domain owner", "W3C markup validation") is already included and can be customized."