Mandelx is a very fast fractal generator that uses highly optimized assembly routines for calculations (multithreaded). Integrated palette editor, palette animation, Record to AVI, and direct rendering to virtually unlimited picture sizes supported.
While the precision is enough MandelX uses the appropriate 32 bit SIMD floating point code path (SSE ,3Dnow!), then switches to 64 bit SSE2 and finally to FPU code. However you can switch between different code paths manually too. The FPU code uses 80 bit extended precision data so you can zoom deeper - without loss of speed - than with most other fractal generators. Source code is included.
Anyone who is interested in fractals. Since the package includes the source code, the assembly routines are available to make experiments.