True, the limit to the creation of chess/engine is human imagination. Check yourself the two top class chess engines that are currently creating new waves, sweeping Rybka-3 and even the latest fritz 12. The best thing is these two engines are free and works well in any UCI capable chess programs...p/s: info as I read from other people's reviews
http://www.filecrop.com/Ippolit.html
http://www.cyclonechess.com/robbolito.htm
If you need a UCI capable program you can download Arena or Winboard