Now author, Daniel Jinguji. MSDN Online is the one place you should look for information on all of Microsoft's developer resources. Controls onto forms or HTML pages.
Applets are a separate technology for adding interactivity to Web pages.
Deriving from UserControl is no good option because I have to build the controls from ground up. Simple derivation from exisiting WFC Controls would be much easier. You can create controls by subclassing other controls but, unfortunately, you will not be able to work with them in the Forms Designer. We aren't able to talk about features of future versions until they have been announced. I am not aware of an easy way to add command-line tools into the development environment.