Yahtzee is a board game released by Milton Bradley (now owned by Hasbro), invented two years before by a couple of canadians.
Although it's a commercial game, it can also be played with just five dice, some pencils or pens and sheets of paper, and the knowledge of the rules and scoring categories.
The objective is to get some combinations, as what happens in poker, having a "Yahtzee" when the five dice has the same score.

Y'ahztee is the computer version for Amstrad CPC and MSX, created by Dimension New and Idealogic.
It gives you the oportunity to play the game without other persons. The graphics are very simple, it's slow (probably coded in Basic) and it doesn't highlight in any field specially.