Ever since I was 8 I was hooked on science. Making software on programmable calculators from I was 12. Awkward with people but safe with science. Started reading the encyclopedia from the beginning, wanted to understand why. Inspiring others came later. Now hopefully adding some inspiration in your life.
Fe₂O₃ is my suite of terminal apps, written in Rust with Claude. Until now you had to install an app to see it. Now you click: isene.org/fe2o3/try.
Pick a card. The app starts right in the page. No install, no account, just the app.
What you can try
- funkeys: eight games on my own game engine. Falling blocks, a dungeon by the rules of Amar, a space shooter and more.
- sky: type a latitude and a longitude. You get the sky over that place, right now.
- moon: the Moon as it looks tonight, with a map of its craters and seas.
- stars, exoplanets and universe: named stars, known worlds, and every scale from the quantum foam to the cosmic web.
- elements, isotopes and particles: the periodic table, the chart of the nuclides and the Standard Model.
- alchemy and circuit: a chemistry bench and an electronics bench.
- fractal: Mandelbrot, Julia, Lorenz and friends.
- rpnx: a calculator in the style of the HP-41.
Every card links to the code on GitHub.
The same code
These are the very same programs that run in my terminal. The same Rust code, showing in the browser.
crust draws every Fe₂O₃ app. It can now draw in a terminal inside a web page. The apps hardly had to change. Pictures show in real pixels, as they do in my own terminal (no pixel-faking with braille characters, though it does that too if the terminal can’t paint all the pixels individually).
The games came first: Stack and the Eliminator already played in the browser. Now a dozen apps join them.
Safe to click
An app in the page cannot read your files, reach the network or start a program.
Every scale
One more, right here: the universe, from the quantum foam to the cosmic web.
Summary
Built with Claude in under two hours. Public Domain, like everything I make.
Link to this post: https://isene.org/2026/10/TryFe2O3.html