Fractint originally appeared in 1988 as FRACT386, a computer program for rendering fractals very quickly on the Intel 80386 processor using integer arithmetic.
The 80386 requires the Intel 80387 coprocessor to natively support floating point math, which was rare in IBM PC compatibles.
Early versions of FRACT386 were written by Bert Tyler, who based it on a Mandelbrot generator for a TI-based processor that used integer math and decided to try programming something similar for his 386 machine.
In July 1990, it was ported to the Atari ST, with the math routines rewritten in Motorola 68000 assembly language by Howard Chu.
Iterated Dynamics is a fork based on FRACTINT 20.04 patch level 4, with source code on github.