The Irrlicht Engine is an open source high performance realtime 3D engine written and usable in C++. It is completely cross-platform, using D3D, OpenGL and its own software renderers.
emuSICK is a free multiplatform radio automation system based in the QT framework from Trolltech and the best wonderful FMOD sound engine. It allows to play multiple playlist grouped in blocks of time. You should use it in Linux, Windows and Mac.