To run the main Game of Life implementation, compile all the java files to class files, and then load the GameOfLife class as main to run the program. To run the alternative threaded implementation, change directory to ./altthreadedimpl/, compile those java files to class files, and load that GameOfLife class as main to run the program.
There is no meaningful difference in performance between the two implementations. The first implementation was found to chug and be laggy, so I tried a threaded implementation that used distributed processing across 16 worker threads (since my machine has a 16-core processor).
This didn't prove to be a solution; I got hold of a Java profiler and examined execution, discovering that the bulk of the processing-- 87% of processor usage-- was happening in the java.awt.Graphics.fillRect() method that was being called 10,000+ times per step of the algorithm to paint every single live or dead cell to the viewable area where the cell grid was displayed. Due to a tricky bug the number of calls to fillRect() could not be reduced; within the limits of my Java knowledge, Java doesn't run fast enough to implement Conway's Game of Life at a satisfactory pace with smooth animation.
I consider this project a failed one, due to the optimization issues. I preserve both implementations here for posterity; in particular the threaded distributed processing implemented in the alternate threaded implementation is a good example of that kind of solution, and I save it here for reference for the next time I'm solving a problem like that.