In the end, only 12 Derivatives will be playing.
First off, Houdini, Critter, Rybka wont be playing even if they're considered by some to be derivatives.
Direct clones of other programs also will likely not be among the 12 participants. Examples are ComStock, Ryanfish, and Tactico.
If anyone here knows of any string, but unknown derivatives I may be missing, let me know so I can look at it.