The 7zip tool has a command line program to go along with the GUI integrated into Windows explorer. This is well documented here.
High performance fractal viewer written in Java - beautiful images, and good performance. Seems scalar loops in Java get good performance, and you can write a portable GUI on top and have arbitrary precision maths support from the libraries. The symmetry in chaos book describes interesting fractals. Its a sign of changing times that the example programs were written in QBasic.
Some C++ objects are non-copyable. Some patterns recur. Heh.