games/exchess 7.97beta NetBSD

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.