Twintsam

From WHATWG Wiki

Twintsam is a project to create an HTML5 toolbox in C# for Microsoft .NET 2.0 (no .NET 1.0 or 1.1 compatibility).

The first goal is to have an HTML5 parser, then add (in any order) a serializer (with optional tags knowledge and other byte-size optimization tricks), DOM implementation, ASP.NET controls, etc.