What is Rybka?
Rybka is a standalone UCI chess engine which can be used to play chess games or to analyze chess positions.
What is a chess engine?
A chess engine recommends moves and provides evaluation scores for chess positions. It should be used together with a chess graphical user interface (GUI), which will provide intuitive graphical interaction with the engine.
What graphical user interface should I use with Rybka?
You can buy Rybka with the Aquarium GUI or the Fritz GUI. Both GUIs support Rybka well and can be fully recommended. Alternatively you can buy Rybka without graphical user interfaces (GUI) and use it with any interface that supports UCI-engines.
Some major chess GUIs (in no particular order) are:
From this list, Arena is free and is easily the best free chess graphical user interface available. It can be downloaded from here.
How many versions of Rybka 4 do I get when I make a purchase?
There are no major updates planned, Rybka 4 will be a single release.
Do I get the 64-bit version also, when purchasing Rybka?
Yes, both 32-bit and 64-bit versions are included.
My processor has multiple cores, should I buy the multi-processor/deep version?
If you want Rybka to use all the cores of your processor, yes.
Is there any difference between the multi-processor/deep version and the normal version besides that?
No, on a single-core cpu there is no difference in playing strength.
Are there official opening books for Rybka 4?
Yes. Rybka's commercial opening books are written by Jiri Dufek and are available in .ctg and .hsh format. They are sold separately by Chessbase and ChessOK. Read more.
If you'd like to learn more about Rybka, you're welcome to join us for discussion on our forum: www.rybkaforum.net