libvisual, which may come in handy if I ever rewrite the Windows Media Player <-> .NET integration I did a while ago - http://libvisual.sourceforge.net/
I've learned a lesson the hardway... don't rely on the VB/C#/C++.NET's automatic object serialization. Always implement ISerializable. For more details: http://www.vbinfozine.com/a_serialization.shtml