Ultra FractalUltra Fractal ~ v5.04 ~ SHAREWARE
OS: Win/MacOS X
author: Frederik Slijkerman
url: http://www.ultrafractal.com
alt: English | Español | Deutsch
Ultra Fractal is a very powerful  fractal generator which holds a large, loyal and growing following. It comes with many (yes, many), fractal formulas and coloring algorithms to choose from, layering capabilities, image import, transparency, and plug-ins availability. You can even take advantage of other computers on your network to calculate your fractal images. There are three versions with varying prices: Extended ($99), Creative ($49), and Express ($29). There’s also a discount for owners of previous versions (see the website for details). This is the only openly commercial package on this list because it’s been the most popular generator among fractal enthusiasts and because it comes in several languages (a big plus).
Last revision: 11 August 2010.

Windows Chaos Image Generator Windows Chaos Image Generator ~ v2.00
OS: Win9x/NT/2000
author: Thomas Hövel
url: http://www.th-soft.com
WinCIG is another very simple Mandelbrot set generator that is very easy to use. Most of its processes are automated, so users only have to use the mouse to draw a little rectangle to cover the region they want to zoom in. Automatically, a small window with some extra parameters will pop-up, allowing the modification of any value. It also comes with a palette editor. Images can be saved in BMP format.
Last revision: 19 August 2002.

Xaos GNU Xaos ~ v3.6
OS: Platform Independent
author: Thomas Marsh and Jan Hubicka
url: http://matek.hu
alt: http://sourceforge.net
XaoS is a real-time fractal zoomer that can calculate Mandelbrot and other fractals significantly fast and on the go. Supports palette changing, and the images can be saved in PNG format. New version is only available as a platform independent package (that is, same package for multiple operating systems, specifically: Windows, BSD, Mac and Linux). It’s an open source project, so the source code is also available.
Last revision: 2 November 2013.