I have just released a new version of BJStrike blackjack simulation and practice software. BJStrike runs natively on Linux, Windows, Max OS X and Solaris operating systems. BJStrike combines simulation, index generation, hand analysis, deck segment manipulation and card counting practice modules into one package. For information, demo versions and on-line simulation see:
http://www.dftsimulab.com/bjstrike/
The changes in Version 4.0 have been focused on streamlining the options for Spanish 21, improving user friendliness and adding more rule variations. Free upgrade to Version 4.0 is available for license holders of older versions.