After working on and off on it, I have finally completed the VirtualTaj interactive 3D walkthrough of the famous Taj Mahal. The demo uses OpenGL and SDL and runs on Windows and Linux. You would need a PC with a 3D accelerator card to enjoy this demo properly.
The original demo was published by Intel India - the DirectX code for the original demo was written by D Sanjit and the 3D models and textures were created by VR Real Technologies. Thanks to all of them for making this demo possible.