https://github.com/hqkirkland/Netshout/
I figured it was time that the SHOUTcast community had an open-source example of how to use the Ultravox/2.1 protocol, and a library with which build source clients. Here's my release!
I'm fairly certain it's not thread-safe since I really don't understand threading (I'll work on that if there's demand) but from what I DO understand about it, I'll go ahead and guess that multiple threads don't really need I/O access to this stuff.
For examples on how to use, see the NetshoutTestbench folder. Contains my code to test the library. I do recommend a basic understanding of the overall Ultravox procedure (order in which to send packets), but other than that, anyone with a good understanding of .NET should be able to pick this up.