The final game I want to examine is the best available, in my opinion. Superchess Two is from CP Software and is a chess player's dream. The range of options includes 10 levels of play, a recommended move option, self-play, analyse and technical information.
The self-play mode pits the computer against itself so that you can see how it solves game problems. You can also provide it with problems to analyse and solve.
The most advanced level is level 10. At that level the computer can take several hours to make up its mind about a move.
The game also includes an option which I have never seen in other chess programs. The technical information option will tell you how the program is structured and which techniques are used for the computer to find its next feasible move. Explanations of tree searches and data structures is provided to give the player a chance to further the computer's 'mind'.