Parallel processing has been used to increase performance of computing systems for the past several years. In principle, parallelism can be achieved by using a large number of processors. However, effective parallelism can be achieved by exploiting parallelism available in program structures. Program loops also provide a great opportunity for exploiting parallelism. The basic goal of loop parallelizing techniques is to maximize the degree of parallelism and improve data locality within and across loop nests. Automatic parallelization of loop-based programs will play a very important role in facilitating the use of high performance computers. With the above in view, and the current interest in this topic, we are publishing this special issue of The Computer Journal.