Computer simulation is the third way; in science, complementing the traditional disciplines of theory and experiment. It allow one to do experiments on a computer - a kind of virtual reality in which one can study everything from subatomic particles to galaxy formation. There are several approaches to computer simulation. An important one is Monte Carlo (MC) simulation. This uses computer generated random numbers to mimic the effects of thermal fluctuations encountered in liquid and solid materials such as are commonly studied in Chemistry, Physics and Chemical Engineering. In recent years great effort has been dedicated to developing ever more sophisticated MC algorithms which allow one to study more and more complex materials and phenomena. However these algorithms are themselves becoming so complex that they can't be easily implemented separately by individual research groups. Indeed to do so would be a wasteful reproduction of effort. There is thus a need for algorithmic experts to write software which can be easily shared with other researchers. This software will need to be carefully constructed, efficient, portable, well documented and well supported. The main aim of this proposal is to meet this need. It will involve a team of experts experienced in design, implementation and application of Monte Carlo algorithms constructing a general purpose suite of software which will be readily available to users in academia and industry, and supported by appropriate training.