Mirek's MCell is perhaps the most comprehensive Windows application for playing with Cellular Automata.
The following rules in the "Weighted Life" architecture will all result in fractal replicators, with differently shaped layouts. Any starting configuration of active cells in these CAs will be replicated endlessly in a self-similar layout
The first 9 values of each rule specify the weights of the neighbors being considered. "HI0" specifies that there are no history states or intermediate states between a cell's active and inactive states. "RSx" and "RBy" signify that a cell survives if x neighbors are active, and that a cell is born (becomes active if previously inactive) if y neighbors are active, respectively.NW1,NN0,NE1,WW0,ME0,EE0,SW0,SS0,SE0,HI0,RS0,RS2,RB1 Perfect Sierpinski layout NW1,NN1,NE1,WW0,ME0,EE0,SW0,SS0,SE0,HI0,RS0,RS2,RB1,RB3 Double nested triangular layout NW0,NN1,NE0,WW0,ME0,EE1,SW0,SS0,SE0,HI0,RS0,RS2,RB1 Angled Sierpinski layout (grows along a 45 degree diagonal) NW0,NN1,NE0,WW0,ME0,EE0,SW0,SS0,SE1,HI0,RS0,RS2,RB1 Sharply angled Sierpinski layout
NW1,NN1,NE1,WW1,ME0,EE1,SW0,SS0,SE0,HI0,RS1,RS3,RS5,RB1,RB3,RB5 2:1 rectangles with an empty horizontal bar in the lower part NW1,NN1,NE1,WW1,ME0,EE1,SW1,SS1,SE1,HI0,RS1,RS3,RS5,RS7,RB1,RB3,RB5,RB7 Upside down version of the previous rule
NW0,NN1,NE1,WW0,ME0,EE1,SW0,SS0,SE0,HI0,RS0,RS2,RB1,RB3 Also known as Rule s1357/b1357 in a Life CA. Grows equally in all directions
Sujai Kumar, March 2005