Midi Player Sample

I am currently working on a student research project dealing with sound processing. I have been trying to play midi files at a low level, reading and then sending each midi message, but I have found very little documentation on how to do this and even fewer examples. I would greatly appreciate if anyone could point me to some sample code or good documentation. Either Unix or Windows code would be best. I’ve been trying to teach myself how to use the windows platform sdk midi functions, but withlittle luck.