iota aims to be a tiny C chess engine, supporting the full rules of chess, as

well as a standard protocol. More precisely, it aims to:

1. support (a subset of) a standard protocol (UCI or CECP) such that a full game

can be played, and

2. for every *legal position* in which a legal move exists, be able to give one.

Where we define a *legal position* as one which can be reached from the initial

position by a sequence of legal moves. It includes the full game state. While it

may be arbitrary, we require a standard protocol because one could imagine a

pathological protocol where the GUI sends a list of legal moves, from which the

engine then selects one. This would reduce the exercise to writing the smallest

program which repeatedly choose the first move (say).

For the first criteria we use the UCI protocol, in particular the following

commands are used: 'uci'/'uciok', 'isready'/'readyok', 'position' and

'go'/'bestmove'. While iota does obey the second requirement - so accepting

en-passent captures, under-promotions and castling - it will never castle

itself. Note that this is not a violation because if we have the option to

castle, then we always have the alternatives of simply moving either one of the

king and rook toward the other.

I would like to give thanks to H. G. Muller (HGM) both for his engine MicroMax

and its description, and also for his practical

[definition](http://home.hccnet.nl/h.g.muller/definition.txt) of a chess

program: