30 Years of XaoS:
Past, Present and Future

An anniversary meeting in Czechia
on 19 September 2026

Where: České Budějovice, Czechia, Gymnázium Jírovcova 8, https://jirovcovka.net/en
When: 19 September 2026, 14:30-17:30 Central European Time

XaoS is a free software tool that allows users to explore and render various types of fractals, including the Mandelbrot set, the Newton fractal, the Sierpiński triangle and carpet, and the Koch snowflake. The program enables real-time zooming to extreme depths, meaning that computations are performed instantly. As a result, users can explore fractals as part of an interactive journey, without requiring prior mathematical knowledge.

By adjusting various settings and entering user-defined formulas, it is possible to create a wide variety of stunning images and animations. Users can save and load their creations, and share them online via the website xaos.app . The program is available in 17 languages (including Czech), thanks to the dedicated efforts of the international XaoS community.

The XaoS project was started 30 years ago by Jan Hubička, then a young Czech student at Gymnázium Jírovcova 8 in České Budějovice, and his friend Thomas Marsh from the United States. At the dawn of the free software movement, developing real-time fractal animation software in the C programming language was a remarkable achievement. XaoS soon became part of the GNU Project and an official package of Debian Linux. Over the years, it has been ported to a wide range of operating systems and eventually rewritten using Qt to ensure maintainability across a vast number of platforms, including the web.

At this meeting, we celebrate the collective efforts of the XaoS contributor community, honour the original authors Jan and Thomas, reflect on the past 30 years, and look ahead to the future. Contributed talks will recall the first challenging steps taken in the city of České Budějovice—an open-minded city with many talented young minds. Selected highlights of the mathematical, technical, and programming challenges will also be presented to inspire the audience to contribute to science, the free software movement, and society.