This is a Yahtzee game written in Java. It's free to download and distribute etc. You can download it by clicking on the link below. You will need a Java Runtime Environment to be able to play. If you don't have this installed you can download it from the Java website.
Playing the game should be fairly intuitive. Click on 'Roll' to roll the dice. Then click the dice you want to roll again, and repeat until you have a nice combination or you run out of rerolls. Click at anytime on any of the highlighted scores on the scorecard to use that score. The score you will get is shown in brackets before you click on it.