Fritz 11 is an excellent program for studying chess. It's around $50-60, but well worth it.
computer program for end game study?

Hi Knightly
I have Rybka 3, the worlds greatest chess program. What I'm actually looking for is a computer program that teaches END GAME through tutorials, repetition and theory. I've found only one: chessmaster. However, it stinks. There must be a better one out there!

ChessOK/Convekta has a program called Comprehensive Chess Endings, that is an electronic version of Averbakh's series of ending books. It has exercises, and the ability to practice positions against an engine, plus all of the info from the books. You should be able to find it for $40 or less.
http://products.convekta.com/664/2/
Does anyone know of any type (besides cheap Chessmaster) of a computer program that teaches, and allows practicing End Game study?