With this applet you can explore all totalistic cellular automata with two states and 4 neighbours. The "rule" field is a description of the rule: "B" is followed by the number of states (0..5) which are necessary for birth (setting the cell active, if it was inactive) and "S" is followed by the number of states (0..5) which are neccessary for survival (the state remains active, if it was active before). For example the rule "B134S3" means, if the center is empty and there are 1, 3 or 4 active cells around, the center switches to active and if the center is active and the number of surrounding active states is 3, the cell survives. All other number of active neighbour cells results in an empty cell. There are 512 different rules.
Below are some examples (the first one is the initial configuration). Enter the rule in the rule field, click "Set", enter the density in the density field and click "Seed". If it is flickering to much, try clicking "Switch Flickering".
The source: TotalisticCellularAutomaton.java and TotalisticCellularAutomatonCanvas.java