SpiffyWare HtmlTransformer (.Net Class Library) Description:

HtmlTransformer is a .Net class library that you can call from any .Net language. This class library allows you to transform text input into safe HTML display content. You can use it to convert text from user input into different safe variants of HTML. You can even choose individual tag sets to allow and even which types of links are allowed within those tags. For example, you might choose to only allow local links to prevent users from jumping off site. HtmlTransformer supports high level modes as well as granular members for determining what types of transforms you can apply. In addition, HtmlTransformer supports the conversion of text formatting like BB (e.g. [b]...[/b]) and SimpleFormat (e.g. *...*, /.../).