From Orbis Systems:
"HtmlSource Viewer" is a simple yet powerful utility for in-depth viewing and analyzing any web page source code. It was primarily designed for web developers seeking a quick and easy way to analyze and debug web pages they are working with, but could also be used by anyone looking to see "how things are actually done" on any website on the Internet.
Web pages are becoming more and more complex these days, with HTML being generated dynamically on both server and client side. Those pages can include FRAME and IFRAME elements, client side scripts, DHTML, Internet Explorer modal dialogs, etc. "HtmlSource Viewer" addresses all those issues by providing handy and easy-to-use real time interface for viewing web pages source code in full details.
Displays HTML source code that exactly matches visible content of the page, but can also show HTML source as it was loaded from the server.
Shows separate source code for every element currently under cursor allowing to quickly browse through the source as your cursor moves across the page.
Allows viewing HTML source code in Internet Explorer modal dialogs.
Can be used to browse HTML source code in any program that uses Internet Explorer internally - Html Help like this document for example.
Allows executing of custom user scripts in a context of any web page currently loaded in Internet Explorer.
Lets browsing subdocuments hierarchy of FRAME and IFRAME tags.
Allows executing of "Break At Next Statement" command to break script at the next statement and attach a script debugger to Internet Explorer (script debugger has to be installed on a local machine).
Handy HTML, CSS and Script syntax highlighting.
Displays properties and current style of HTML tags.