It is a free, lightweight, easy-to-use tool for developing ASP.NET Web applications.
Makes building ASP applications significantly easier than other tools available
If you've never tried ASP.NET, then Web Matrix is a good place to start
It generates HTML for you
A couple of drag-and-drop operations can create a simple but functional Web application
You can either directly edit the HTML code or make changes in the Design view
Contains various "views" of an ASP.NET Web page
both the source code and HTML
just the HTML
just the source code
WYSIWYG Designer