Barnsley is a tool I’ve created to visualize iterated function systems, like the one shown above. You can access it via the website or by building it yourself from source. You can find the source code for the library and for the graphical user interface(GUI) on GitHub. The GUI is currently implemented using Rust’s egui. Let’s back up a bit though. What is an iterated function system? An iterated function system or IFS is a formal mathematical structure.