NSF Play is a Nintendo Sound File player for the Gamepark 32. It was designed with a very minimal focus on making sure the GUI was pretty and a heavy focus on trying to make sure that there was little skipping. Unfortunately, there still seems to be a tiny amount of skipping in the latest version. Be advised that this project is mostly dead. If you're interested in the original version (admittedly a port of NEZamp), you should look at a mirror of xmms-nsf at Zophar.net.
Do note, you need Marko SDK v0.85, along with the above patch to compile this software.
Kuwanger.net - Sort of like stag beetles in tubes.