Computer simulations are another way of obtaining fundamental information about interacting condensed matter in addition to traditional theoretical and experimental approaches. Development and refinement of large scale computer simulation approaches to study phase transitions in systems with competing interactions, which are both more realistic as well as more difficult to treat analytically than more simplistic models, will continue. Approaches which will be used include Monte Carlo, Monte Carlo Renormalization Group, Molecular Dynamics; and Spin Dynamics methods. Models which will be considered are expected to be relevant to magnetic materials, cubic binary alloys, physisorbed/chemisorbed monolayers on crystalline substrates, and disordered media. Additional effort will be devoted to the study of linear and non-linear excitations in low dimensional systems. The results will be compared with those of theory and/or experiment.