A couple of weeks ago, just before the Anand-Toplaov match (now tied 5-5) began, I came across & downloaded a free chess engine, Firebird 1.2, that rivals Deep Rybka 3 in strength but may be a fishy knock-off.
While not being qualified to debate or moderate the clone claims, I can offer the following observations:
- Firebird 1.2 is a "Deep" engine, able to use more than 1 processor.
- It calculates considerably faster (30% or more) than Deep Rybka 3; which is a big plus when you are reviewing & annotating games.
- Firebird loads effortlessly in ChessBase 10 whereas Rybka sometimes fails to.
- The 2 engines recommended the same move just 43x out of 59 in the 1 game I tested (Tomkovich-Moldovan : GSCL 2010) & had differing evaluations + lines or play.