You need an interface which can work with UCI modules. Arena is a good (and free) one.
How to actually use Fruit?
Thanks for your very helpful answer! I will check the Houdini as well.
Is there also a freeware engine where I can place new pieces on the board (while playing) and then make it calculate the next move with the new piece taken into account?
- Have a functioning set of teeth and digestive system.
- Ensure the fruit is edible.
- If the fruit has a tough skin, peel it off with a knife.
- Bite into the fruit.
- Remove a small piece of fruit from the fruit with your teeth.
- Chew until the piece of fruit is a mush.
- Swallow.
- Repeat steps 2-7 until the fruit is eaten.
- Repeat steps 2-8 if there are more fruits.
- Discard the peel from the fruit if applicable.

In Arena, you just press the "edit" button and then add/remove as many pieces as you wish on the board. The engine itself is pretty irrelevant.
Instert it into your mouth and chew. When it reaches desired conistancy you should swallow. With some practice it will become almost second nature.
EDIT: I probably should have read the thread first.
Fruit is indeed a strong engine.st freeware engine.
Good luck!
PS: For more costly opportunities, check out ChessBase products. I use Fritz 13 for my daily chess-related purposes :)
I used it to test a game for a new chess variant: economy chess. You get money from the squares you occupy and buy new pieces.
I think I got the houdini to work in arena, and two times I managed to let it play a bit against itself and adding pieces by using the Set up a position-button. Both games I couldnt get the engine to do what it needed to and had to abort after 15 moves or so :/ Ill try again later :)
The engine doesnt take the income from the realm you own into account, and I had to judge where houdini would get his new piece.. my judgement is not the best to say the least. But it was fun to see the variant being played by a smart player! Thanks for the help and also thanks for advice on nourishment :P




Sorry for the noob question.. but how do I use Fruit?
It appears that I need another engine, like fritz? anyone knows where I can find an engine that makes Fruit work?
Thanks!