Component-Based Development with Visual C#

http://www.codeproject.com/KB/books/0764549146_8.aspx

The Microsoft WebBrowser Component

One of the most powerful reusable UI components I know of is the WebBrowser ActiveX component used by Internet Explorer. Microsoft designed it to be extremely flexible in terms of the kinds of content it can display. Obviously, it can display HTML documents, but it may come as a surprise to some of you that it can also display other common file types such as Word, Excel, PowerPoint, TXT, RTF, GIF, JPEG, XML, PDF, and others. WebBrowser achieves this incredible flexibility by using an embedded ActiveX component to render its data. In the case of HTML documents, the component is MsHtml. For more complex documents like Word or Excel, WebBrowser acts as an Active Document host and embeds Word or Excel in the client area to handle the rendering.