HTMLDocument Class Library

HtmlDocument class library provides you with the DOM (Document Object Model) for the HTML documents. The same way the XmlDocument class provides the DOM for the XML documents the HtmlDocument does that for HTML documents. HtmlDocument library provides the light-weight high-performance HTML Document Object Model engine.
HTMLDocument is 100% native .NET framework managed component written in C#.

HTMLDocument fully supports ASP.NET, however trial version will not work under ASP.NET because trial message box dialog is displayed. You can still fully evaluate component in non ASP.NET environment to see whether it satisfy your needs.

HTML

HTML is not well-formed format like XML, so there are lot of complexities that are involved in trying to provide consistent in memory, tree-like Object representation. Most of the pages on the Internet are not well formed thus not suitable for parsing with the XML objects provided by .Net framework.

The HtmlDocument class library will accept the standard (not well formed) HTML and create the in-memory tree like document object model from it.

XML

HtmlDocument library will also create the XmlDocument from current HTML DOM so you can use full power provided by XmlDocument class directly on your HTML.