Epitaxial growth is controlled by an interplay between thermodynamic and kinetic driving forces. The role of kinetics is especially obvious in unstable systems such as growth of strained heteroepitaxial layers. In particular, for growth of alloy strained layers, kinetic effects can dramatically influence morphology and alloy composition. Some recent progress in understanding V heteroepitaxial growth of strained alloy layers is briefly reviewed. (C) 2002 Elsevier Science B.V. All rights reserved.