Press the green flag to start it rendering, I would suggest using turbowarp.
Update: I was wrong, after a conversation I had with @AO-85757 on the subject, I have learned that there is no 3D Mandelbrot Set. Before you post a comment saying that this isn't a 3D Mandelbrot, let me explain the method to my madness. So first of all let's go to the basics, how you turn a Square into a 3 Dimensional object, you simply add another square, place it along the Z axis, connect them together and they become a Cube. Simple, what's not so simple however is doing this to a Mandelbrot. So we must simplify the Mandelbrot, a major structure is the two fractal trees that extend outwards from the Mandelbrot. I simply placed one of these trees along the Z Axis facing towards you.(The lightest part.) Now to fill in the empty space I chose a layering of the Mandelbrot that would look like depth(The layering uses a few of the patterns you see in a 2D Mandelbrot to work) Whether or not this actually exists in a 3D Mandelbrot is not something I can know at this point in time. And the next part is something which is beyond my skill level, to create an accurate 3D Mandelbrot you would have to take each individual part and make it 3 Dimensional, this is extremely difficult and beyond my skill level, an easy way to do this would be to split up a low iteration mandelbrot into simple shapes, and place them along the Z axis. The position of the trees in a 3D axis can be demonstrated by an example: You have a tree which has 3 branches, this would have 6 branches in total in the 3rd dimension, you would divide 360 by 6 , resulting in the number 60, you would then place a branch 60 degrees along the Z axis, 120 degrees along the Z axis, and repeat this until you have placed all 6 trees. Sadly I cannot program this with my current skill set, if someone could help me out with this I would appreciate it deeply, until then I will have to wait until either this theory is disproved, I get the skill set needed, or someone else makes it for me. Credits: @Cyclone103 for the 2D Mandelbrot I used.