Just testing Apophysis7x-lite (with only 59 max. transform) with Direct Coloring feature. And also testing the mandelbrot plugin (unreleased) by ~Lu-Kout
But is it a full complex engine, or just the Mandelbrot? I mean, there's a difference... for Mandelbrot, you only need... let's see, if f(z)=z^2+c, and let's say z=a+bi and c=s+ti, then f(z)= (a^2-b^2+s)+(2ab+t)i. See, you can define it all in split axes, and treat it as if it were a real function. To make the whole engine, you would need to define all of the operations... including ones like exp, which would be fairly difficult.