From Balazs Tihanyi:
ForgeDoc Portable is a fast, powerful and easy-to-use documentation generator for your everyday development needs. Just drag and drop your assemblies in the project editor and build your desired API reference documentation within moments. ForgeDoc Portable completely supports .NET Framework 4 with the latest C#, Visual Basic and C++ syntax. You can create your documentation in HTML format or a single CHM Help file. You can also generate localized output in multiple presentation styles, including past and current MSDN look.