Part of the question is what do you want the language to be like. Maybe you want the full power and flexibility of C#. Or maybe you want it to be a little simpler so people can use it who may not be real programmers.
I just posted my Silk library on GitHub for .NET. It takes the second approach and has a language without excessive punctuation and isn't case sensitive. It also is very loose with data types.
It's very easy to use. Just register the functions your code makes available to the script, compile the source to bytecode, and run it. When one of your functions are called, an event is raised and your code can implement that function.
