The HtmlEditor is a C# wrapper for Microsoft's Mshtml COM component. Mshtml is the part of Internet Explorer which renders HTML. It also has an edit mode which makes it relatively easy to create a GUI editor that generates HTML. Since it is a .NET assembly, the HtmlEditor can also be used with Visual Basic .NET or any .NET language. However, because it invokes a native Windows DLL it will not work with Mono or other .NET implementations on Linux or the Mac. The HtmlEditor is presented as a sample: it is free for both commercial and non-commercial use.
Visual Studio .NET also supports using Internet Explorer as an ActiveX control. This is also a viable approach, and probably better if you want to embed a web browser in your application. However, some people have run into problems with the ActiveX control, and the HtmlEditor is easier to customise. If you want to display and/or edit HTML, the HtmlEditor may be a better solution.test and it is a smaller footprint too.