Wow. Sure has the great grandaddy of fractal software beat six ways from sunday. Check out FractINT.
http://www.fractint.org Originally developed for DOS (Why? Because Windows wasn't invented yet when FractINT was started!) and has been ported to Linux and Windows. DOS version is the most developed, now at version 20. Windows version has been stalled at 18.2 for some years.
FractINT made a bit of geek history by being the first program to use the GIF89a image format. It uses the extra data to store in-progress calculation of several types of fractals. Yup, a pause feature.
That was quite important when it'd take WEEKS to calculate a single deep-zoomed image on a 486SX. (And some people ran this on an 80286* without a math coprocessor!)
The original point of FractINT was to prove that fractals could be calculated using only integer math, without using a floating point math co-processor. (Though it can use one if you have one, and whose PC doesn't these days?)
*A weird design feature of the IBM AT and most clone 286 PCs was the 80287 math chip ran at 2/3 the speed of the CPU. Several companies sold special interposer sockets with their own crystal to run the FPU at the same speed as, or faster than, the CPU. Near the end of the 286 era, the 287XL was developed which had a built in 1/3 clock mutiplier to run at full CPU speed. Just some of the trivia one accumulates having been a computer (ab)user for 23+ years!
