A highly interactive, integrated and multi-level simulator has been developed specifically to support both the teachers and the learners of modern computer technologies at undergraduate level. The simulator provides a highly visual and user configurable environment with many pedagogical features aimed at facilitating deep understanding of concepts which are often difficult to grasp by the students. The rational behind the development is explained and the main features of the simulator are described. A brief account of the ways in which the simulator has been used to support undergraduate lectures and tutorials is given. The current state of the research in assessing and evaluating the value of the simulations at undergraduate levels is presented.