The Brookhaven Computational Science Center brings together researchers in biology, chemistry, physics, and medicine with applied mathematicians and computer scientists to exploit the remarkable opportunities for scientific discovery which have been enabled by modern computers. These opportunities are especially great in computational biology and nanoscience, but extend throughout science and technology and include, for example, nuclear and high energy physics, astrophysics, materials and chemical science, sustainable energy, environment, and homeland security. To achieve our goals we have established a close alliance with applied mathematicians and computer scientists at Stony Brook and Columbia Universities.