Many years ago, when fractals were new and exotic, I spent a lot of time creating fractal images. Here is a gallery of images that I use as a demonstration for our ThumbNailer application.

Here's one of my favorites:

I wrote my own app to create them, of course. And spent weeks optimizing the inner loops to run as fast as possible (integer-based math, in assembly. duh). I even went so far as to write my own window-based user interface for the app, so it would be easy for me to use. Note that I didn't write "Windows-based" - No, I actually created my own windowing interface, in a hi-res DOS graphics mode and drew all the stuff myself. This was back in the day before Windows 3.1, and I was trying to copy X-Windows and Solaris, not Windows. It was event-driven, had overlapping windows, sliders, buttons, text boxes and screen savers! Quite slick. I also used the windowing system for a primitive coin cataloging application (during a brief interest in coin collecting).

I can still run the fractal app, but because I can't recompile it (I can't find the VESA graphics libs it needs), I can't change the type of fractals it makes. And I just don't have the energy to rewrite it for Windows. So, it's stuck with basic Mandelbrot calcs forever. So sad.