his article describes VRAM, short for Virtual Reality Aided Modeler. VRAM is a conceptual design tool supported by Virtual Reality technology and an ongoing testbed for theory and methodology in the field of three dimensional user interfaces (3DUIs). The outcomes from the project should consist of an intuitive and comprehensive immersive surface modeler, next to a set of taxonomies and guidelines for the development of 3DUIs. Based on a modular structure, VRAMs program architecture allows the easy extension of functionality. The application consists of the seamless integration of four main functionality modules, namely system control, viewing & browsing, editing and modeling. Based on the premise of portability, the software environment runs on both SGI Irix and MS Windows NT platforms. To be relatively independent in developing 3DUI techniques, the VRAM environment supports a multiplicity of input and output devices. Due to the focus on immersive modeling, tracking devices, head mounted displays and stereoprojection devices are the main I/O channels. In this article, we will primary focus on the functionality of the virtual modeller.