[1] In serial simulations of a parallel model, there is an executive that computes each unit in turn, however the particular implementation does not affect the model itself.

[2] A molecule matches another by having a complementary configuration which fits the other molecule like two pieces of a jigsaw puzzle.

[3] ftp://tierra.slhs.udel.edu/

[4] This screen dump is actually from Boppers, a more recent version of Bugland.

[5] The system was not given a title by the authors so it was named after the creatures that inhabit it.

[6] A sense providing information about the state of the body.

[7] ftp://alife.santafe.edu/pub/software/Polyworld