Grid is one of the e-science tools for solving complex scientific problems, which provides access to large computing resources owned by various organisations or even located in different countries. Middleware and fast Internet has allowed combining of these resources in one infrastructure thus resulting in a single high-powered computing machine. Unlike the so-called desktop grid which uses regular computers during the idle time, this grid employs special technology which is usually held by university data centres — mainframes or supercomputers, computing clusters, and data storage facilities. Grid infrastructure may also include various scientific instruments, like telescopes, sensors and other modern equipment, that contribute to more convenient and accessible research possibilities.