OSM interactive viewer like Kosmos

I have student project to create VS C++/C# interactive(supports getting info about features on click or something) OSM viewer. It is meant to work with downloaded .OSM files, like city maps. I have read all i could find about Kosmos(there is almost nothing), mapnik, osmarender etc. but I’m still unsure where to start. I’m also new to creating any parsing XML and 2D drawing application so i would appreciate any help and suggestions.

BTW this should be my master degree work and it is not meant to be easy.

Perhaps not totally what you are searching for, but QGis has a couple of experimental osm plugins, one that reads .osm file and another that can also write.