I am a vc++ developer (but like Qt) interested in learning from open source project by contributing and reading the code. I use windows as primary development platform. Whic
Well I think there is a lot of interesting opensource projects using c++. Boost is the first project one can think about. It is a library, but very well written, so you will learn a lot. If you want something more fun you can try something like a game engine like Ogre3D. If you want to participate in a project with Qt bindings, I suggest projects related to KDE as they mainly use Qt, AFAIK.
Boost
Ogre3D