Interesting request.

In the parallel processing side of old Macs, there is this "Power Fractal Software" on the Dauger Research website: They used have one for the 68K but I cant find it. It shows the "processing power" of single vs. parallel connected machines processing the program, which by itself is small.

Here it is. As I remember seeing a demo video of it, it will run as is on a plain mac and with networked macs working in together. The program wants "Pooch" to run in parallel:

http://daugerresearch.com/pooch/top.shtml

The Mandrel Bot program is here:

http://daugerresearch.com/fractals/powerfractal.shtml

Here is a OS 8.6 and older version. Do not know if it runs on 68K though.

http://exodus.physics.ucla.edu/appleseed/ParallelFractalDemo.cpt.hqx

For parallel processing in 68K you need Launch Den Mother and Launch Puppy:

http://daugerresearch.com/LDM/index.shtml

And the UCLA Physics Dept. AppleSeed Project (this is for OS 8, they have for OS9 and OSX, just play with the links...)

http://exodus.physics.ucla.edu/appleseed/appleseed8.html