During the last year we have been working on two projects. The first is to investigate the properties of photonic crystals using parallel computing. Photonic crystals are periodic structures of alternating dielectric constants. We have developed a parallel code using the MPI standard to calculate the propagation of electromagnetic waves using the finite-difference time-domain method on the dual grid (Yee's algorithm). We are using computing resources of the CDIC department at Brookhaven National Laboratory - a linux cluster consisting of 36 Pentium III processors. The code was checked against the experimental and numerical results using a different method. Our first goal was to describe transverse magnetic modes in a two-dimensional crystal with a triangular lattice (air rods in a dielectric medium). One simulation on a 19x19x8 physical grid (each unit cell consists of 40x40x40 computational cells so that the total domain size is 760x760x320) for 50 periods, on 31 processors, takes 50 minutes. The paper describing the results is about to be finished and sent to Physical Review B. Our future interests include photonic crystal fibers, second harmonic generation and optical limiting. Especially for the case of calculating the transmission properties of fibers one needs great calculational power as the grid has to be 10 to 20 times bigger than the one used for the aforementioned problem. The second project is work on the QCDSP machine. The goal was to run a general statistical physics parallel code on a machine specially constructed to solve quantum chromodynamics problems. We are solving the three dimensional Ising problem using Monte Carlo method. We obtained correct results using a simple parallelization scheme. Our next step is to develop further the parallelization and to extend the applicability of the code.