Thanks NN, that looks quite similar to Chess Titans so DS will be happy with it.
I never knew that DH could play chess until he started teaching DS named openings (Ruy-Lopez so far). I think DH has visions of a future chess champion in the family, I think DS will get bored with it by the end of term.
DS is learning chess at school and would like to be able to practise on the computer. One of his friends uses Chess Titans on Windows 7 which DS quite likes, but we don't have Windows 7 and although I can theoretically download Chess Titans it keeps failing.