QVisio is a 3D fractal renderer/explorer. QVisio 2.8 Tycho will be released ASAP. The key features of QVisio are:

• over 30 3D/4D fractal formulas including Mandelbulb, Mandelbox, KIFS and quaternion fractals
• ability to mix formulas for creating your own hybrid fractals
• full GPU support, using OpenCL/CUDA APIs
• full support for multiple CPU/core/thread
• keyframe based video creation with direct to AVI output
• OpenGL 3D scene preview (using marching cubes to visualize fractals)
• post processing effects such as screen space ambient occlusion (SSAO) or depth of field (DoF)
• realistic ray-traced reflections and environmental mapping
• practically unlimited size of renderings
• equirectangular projection mode (for rendering 360/180 spherical panoramas)
• object/background texturing with ability to use spherical panorama images for background
• various methods for surface colorizing including palettes and user defined functions
• support for rendering 3D stereo images/videos (anaglyphs)
• it's (will be) totally free
• many, many more...

got any questions? mail me: Darek Borkiewicz

And this is how it looks like :-)