KPoker was a simple five card poker game which was originally released in 1998. It was included in KDE's games package up to KDE version 3.5. It was never ported to KDE 4. The last available version was released in 2007.
There's wasn't that much to it, really, you'd pick the card to hold and KPoker would immediately tell you if you've won or not - and how much money you've won. It's nothing that made you want to write your friends and loved ones to tell them how hot it was and how they should try it, but it was a nice basic poker game that would give you some fun for at least two minutes.
There's still a page with information about it at http://kpoker.sourceforge.net/