Tegula is a program for displaying and exploring two-dimensional periodic tilings, based on the concept of Delaney-Dress symbols. Tegula was written by Daniel Huson and Rüdiger Zeller, using code by Klaus Westphal. Tegula is written in Java (12) and uses JavaFX.
A paper describing the math, algorithms and software has been submitted. A preprint is available here.
The source files for Tegula are available here: GitHub.