Taprats is a Javaapplet that implements an islamic tiling technique based on the work of Hankin in the early part of the twentieth century, and on more recent papers by A.J. Lee and Craig S. Kaplan. By Craig S. Kaplan and Pierre Baillargeon.
There is a new version rewritten for Windows under the name Alhambra. See here: https://github.com/pierrebai/Alhambra/releases
This small library implements a data structure for Koch curves.
This small library implements the Koch curve, snowflake and anti-snowflake like a Shape to be used like any other Java shape.
You can test the library by compiling the test applet in Files.