Sterling 2 is a fractal software based on the Sterling fractal generator program written by Stephen C. Ferguson. Unlike the original program, which you can purchase for USD 35 from Stephen C. Ferguson’s website at http://tierazon.com/ktaza/fractal/index.html, Sterling 2 is free. Moreover, it comes with a formula editor. Download Sterling 2 directly from Soler’s website.
Additionally, the website provides a link to Soler’s fractal gallery of 1,128 fractals you are welcome to download and use. Here’s a random sample: