CPTracer is an open source ray tracer, coming with a raytracing-specific 3d-editor. It is written in C++ and uses wxWidgets for the editor's interface. That way, it will be highly platform independent. It is going to support real-time ray tracing and there will be the possibility to easily integrate the program in other applications.
These details are provided for information only. No information here is legal advice and should not be used as such.