EXchess is an experimental chess engine supporting the following features: * Support for Tim Mann's XBoard. * Analysis features of XBoard. * Brute force searches to 60 ply (1 ply = a move by one side). * Hash tables for storing positions already visited in the search. * Pondering. (Thinking on the opponent's time.) * Recursive null move pruning. * Quiescent capture search. * Adjustable hash table size. * Adjustable search and evaluation parameters.