This program is the result of a computational astrophysics class, and is intended for folks who know nothing about N-body phenomena but enjoy making interesting little movies. There are other programs of this sort available, but as far as I can tell this one is dozens of times faster than all of them.

To start it off just type "pcgal" in a Windows DOS box. Only the executable is needed but I'm throwing in all the source code and documentation because I'm a nice guy. The program will create two random blobs of "stars"; just hit a key to throw them at each other. A 166MHz Pentium can make a 15000 particle movie at over fifty frames per second! Even a 486 can handle about 5000 particles at a time, and to my knowledge nothing else for the PC can manage so many stars at once.

Note that the program comes with no guarantees; I don't know enough astrophysics to be sure the pictures it produces are absolutely correct. Perhaps others out there can point out differences from reality. Note also that this version isn't very fancy; you can't pick your own initial conditions, you can't save the pictures as BMPs, you can't choose your own colors, in fact the only thing it can do is make fast movies. Well, I'm officially releasing PCGAL into the public domain anyway, warts and all.

Download the whole thing
Download the source code
Download the header
Download the documentation