a) http://computerchess.org.uk/ccrl/4040/rating_list_all.html
b) Deep Blue was dismantled, and was different in that it was specialty hardware not software as engines like Houdini and Rybka are.
That said Fritz and Rybka are certainly much stronger than Deep Blue was. Deep Blue looked at more positions, but its evaluation and I would guess pruning were weaker (i.e. looks at more useless moves than present day software).
Or the most obvious reason, that it barely beat Kasparov in the 2nd match (lost the first) while today's top software would be favored in a match while running on a laptop
Two questions:
a) What would be better, the latest edition of Deep Fritz or the latest edition of Deep Rybka?
b) Is Deep Blue stronger than Fritz and Rybka and Houdini engines, or is it weaker?