Shapari is one of a pair of pattern producing programs by Spelunk Computing (the other being Curvay, also featured here). Shapari uses a set of provided shapes that can be twisted, turned, coloured and combined to produce patterns. It is simple to use, being partly aimed at children, and a pattern matching game is included. There are no menus but ingenious colour pickers, manipulators and overlayers do the work for you. Patterns can be saved in the program itself or exported to an art program clipboard for futher manipulation. Using a manipulator repeatedly, usually produces an iterated type of fractal - see examples below (last 2 rows). For those of a more mathematical bent, manipulators can be edited or designed from scratch - so something for all ages. Full active tutorials and help files included.
Further details and where to get the program are in 'software used' on left.