This paper describes the design and implementation of an Information Technology (IT)-based system called AMADEUS for real-time and adaptive geologic mapping, analysis, and design of underground space. Advances in IT, particularly in digital imaging, data management, visualization and computation can significantly improve analysis, design and construction of underground excavations. Using IT, real-time data on geology and excavation response is gathered during the construction using non-intrusive techniques which do not require expensive and time-consuming instrumentation. The real-time data are then be used to update the geological and computational models of the excavation, and to determine the optimal rate of excavation, excavation sequence and structural support. Virtual environment (VE) systems are employed to allow virtual walk-through inside an excavation, observe geologic conditions, perform virtual tunneling operations, and investigate stability of the excavation via computer simulation. (A) This paper was presented at Safety in the underground space - Proceedings of the ITA-AITES 2006 World Tunnel Congress and the 32nd ITA General Assembly, Seoul, Korea, 22-27 April 2006. For the covering abstract see ITRD E129148. Reprinted with permission from Elsevier.