Everything in the catalog

Visual, interactive tutorial and sandbox for learning git commands and branching.

Combines typing practice with English vocabulary using word lists and pronunciation.

Interactive chess lessons teaching piece movement, captures, and checkmate by playing mini games.

Train a tiny neural network on toy datasets in the browser and watch the decision boundary form.

Demos of neural networks trained directly in JavaScript for classification, regression and more.

Interactive diagram of a small convolutional network classifying images, running in the page.

Runs a small GPT-2 model in the page and shows attention and token probabilities as it generates text.

Demo page for the PathFinding.js library: pick an algorithm, place walls and animate the search.

Game that teaches CSS flexbox by moving frogs onto lily pads with code.

Playable explainer on how cooperation and distrust spread, built around the repeated prisoner's dilemma.

3D walk-through of the computations inside a small GPT-style language model.

Typing practice that adapts lessons to your weakest keys as you type.

Block-based programming editor for making games, stories and animations, usable without logging in.

Practise hiragana, katakana, kanji and vocabulary through short games with many themes.

Game that teaches CSS grid by watering a garden with grid rules.

Online book with live demos of Bezier curve math, splitting, offsetting and intersection.

Hear arpeggios by turning chords into running notes, and see their shapes on screen.

Explore how chords are built and move between them, with colors and sound, using simple controls.

Visualize the harmonic overtones of a note and hear how they add up to a timbre.

Click a grid to make short melodies and loops with simple instruments in the browser.

Sketch melodies on a piano roll by painting notes on a grid and play them back.

Pluck virtual strings of different lengths to learn how length changes pitch and harmonics.

MIDI utility for learning piano scales, chords and more using a connected MIDI keyboard.

Puzzle game that teaches functional programming ideas by composing functions to transform cubes.