We design and implement a cross-platform extendable Virtual Reality system with the MVC design pattern. It aims on cross-platform usage and extendibility which makes users to write VR applications much more easily. And the system can run on multiple platforms like Linux and Windows. To achieve extendibility, we embed the system with the Python script module which makes the system easy to be extended with specific VR logics for making various VR applications efficiently, also we implemented the system by using platform-independent libraries (like OGRE, Python) to achieve cross-platform usage.