Interactive B-Spline demo. Just mouse drag the points and watch the beautiful curves moving.
Originally a Java applet (circa 2010), converted to a standalone Swing app in 2023.
This project was originally written as a Java applet around 2010 — a technology that let Java programs run inside web browsers via a plugin. Java applets were once everywhere: powering interactive demos, games, and visualizations on the early web.
Java applets were deprecated in Java 9 (2017) and fully removed in Java 11 (2018). Browsers had already been dropping plugin support years earlier — Chrome removed NPAPI plugin support in 2015, and other browsers followed. This was a rare case of the web ecosystem actually breaking backwards compatibility. The usual rule of thumb is that you cannot deprecate anything that runs in a browser, because doing so would break a massive long tail of existing websites. This is why JavaScript still carries decades of quirky syntax and behavior (e.g., typeof null === "object", loose equality coercion, var hoisting) — unlike Python, which made a clean break from 2 to 3, the browser can never make that kind of breaking change. Java applets were the exception: they ran via a plugin, not native browser code, so browsers could drop the plugin without breaking the web itself. The applets just stopped working.
In 2023, this project was revived by converting it from an applet to a Java Swing application. Swing is Java's built-in GUI toolkit — it has been part of the JDK since Java 1.2 (1998) and still works today. The conversion was straightforward: the rendering and interaction logic stayed the same, but instead of running inside a browser plugin, the app now opens its own JFrame window and runs as a standalone desktop program.
$ make run
Only requires a Java runtime (java). To recompile after editing the source, run make compile (requires javac / a JDK):
$ sudo apt install openjdk-21-jdk-headless
- OpenJDK 21.0.10
- Ubuntu 24.04