Houdini 1.03a

Houdini engine is a controversial engine, some consider it as a clone of Rybka but many also states that it is an original engine.

But there is no direct proof that it is a product of piracy and no statement of being a clone from the author of Rybka itself. But for knowledge sake and for your convenience I will put it up here.

There is also difference in engine evaluations, you can try this position:
1Q6/8/8/2pK3p/8/5N1q/1P4pp/5Rbk w - - 0 1

It is a Zugzwang position that Rybka 4 fails to find the best move but Houdini finds it. Which is discussed here. So I guess this can be also be used as an secondary engine.

Download All versions: http://uploading.com/files/ca9e123c/Houdini103a-All.zip/

w32- for 32 bit windows
x64- for 64 bit windows
POPCNT- for SSE4.2 cpus, eg. Core i7 or Phenom II

Website: http://www.cruxis.com/chess/houdini.htm