A classic 'edge of chaos' cellular automata.
Blobs of life occupy cells in a 2D grid. Each blob has 8 adjacent cells. However, too many or too few occupied neighbors will cause it to die, due to overcrowding or isolation.
The rules are:
A blob lives if it has exactly 2 or 3 neighbors, else it dies.
A new blob is born in an empty cell if it has exactly 3 neighbors.
The board is simultaneously updated forming many beautiful and fascinating patterns.
When paused (with the space key) markers are shown in all cells adjacent to blobs. These can be clicked to toggle between blob and marker.
There are 7 pages of example life forms. Pause and use the M key.