Monarch, (Monarch Chess)
an UCI compatible, free chess engine by Steve Maughan, initially written in Delphi and re-written in C . Monarch's board is internally represented as an array (Version 1.0 used bitboards and a pre-generated move table), performs PVS with checks searched at the first ply of the quiescence, in conjunction with SEE, killer and history heuristic, null move pruning with R = 3, ETC and IID, and the evaluation based on piece square tables  .
- New version of Monarch UCI engine by Steve Maughan, CCC, February 07, 2002
- Monarch on a fast Athlon XP2000+ or 2.2 GHz P4? by Steve Maughan, CCC, February 19, 2002
- New UCI 2 version of Monarch by Steve Maughan, CCC, April 12, 2004
- New UCI 2 version of Monarch by Steve Maughan, CCC, April 18, 2004
- Re: A new Monarch version!?Soon!?Thanx by Steve Maughan, CCC, Jaly 27, 2005