Sterling2 is based on Sterling, a fractal-generating program written in 1999 by the redoubtable Stephen C. Ferguson. In mid-2007 I contacted Stephen, as I thought that Sterling was an excellent program that lacked one key feature - a formula editor. He told me that adding a formula editor would be a huge job and that in any case the development environment to compile all the parts of Sterling was no longer available, as it is obsolete. However, he encouraged me to do the next best thing, which was to change the formulae in the program. With his help I set up the development environment on my PC and was able to recompile Sterling and to make changes to just one part of the program, ie the formulae. Other parts could not be changed.

Between June 2007 and August 2008, I spent some 100 to 200 hours changing formulae (that's the quick part) and then testing them to see which ones produced interesting images. It turned out that creating good formulae was much more difficult than I expected. In the process I made and saved some 1,600 fractals. That's not counting about 30,000 that I partially made but did not save. I have finished this process, so Sterling2 now has 50 formulae, all different from those of Sterling. You should be able to make interesting fractals using any of the 50. If you have any problems or questions, feel free to email me at tad@

Download Sterling2 for Windows by clicking below (437 kbytes)

The zip file contains brief instructions. There is no installation - just put the exe and dll files in the same directory and fire up the exe. You will be making fractals within seconds! If you wish, you can use the bundled ico file to change the program icon. Here are two screen shots.

Apart from the name (which shows as sterlingwar2 in the title bar and on the About screen), the program looks just like the original Sterling. Note that I have not changed the formula descriptions - these are incorrect in Sterling2. The only part that has changed are the 50 formulae that one can choose from. If you are interested in the maths, here are the formulae.

Is Sterling2 better than Sterling? I don't know, but it has the advantage of being free, ie anyone can download and use the program. Please don't try to sell it though. All the images shown below were created by Sterling2. The captions mention which formula (F) and render (R) were used for each. You can use parameter files from Sterling in Sterling2 (and vice versa), but they will draw different images. It's worth a try.

The 48 pictures in Rooms 20 to 23 do not give a good idea of the wide range of fractals that can be made with Sterling2. They are some of the best I have made using the program, but that's according to my taste, which runs to complex structure, organic shapes, symmetry and sumptuous colours. For instance, there is a disproportionate number of images made using Render 26.

Room 20           Room 21           Room 22           Room 23

I want to stress that all credit for creating this program belongs to Stephen Ferguson. My role was restricted to modifying the algorithms. To use a building analogy, Stephen designed and built the house, I merely re-arranged the furniture. I also want to thank Stephen for helping me to modify his program and for allowing me to release it as freeware, here on my site. Note that the original Sterling program, together with Tierazon and many others, is available for $35 from Stephen's site.

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