Learn to program in your browser

Programming courses whose programs run inside your browser tab; nothing to install.

Java

From your first program to objects, collections, exceptions, files and a project of your own.

Linux + OpenJDK 25 in your browser

21 lessons · 158 programs

From your first script to lists, dictionaries, classes and files, in Python 3.14.

Linux + Python 3.14 in your browser

22 lessons · 206 programs

Build web pages with HTML and CSS, then bring them to life with JavaScript.

JavaScript with types: catch mistakes before the program runs, and let the editor help you write it.

Make 2D games in TypeScript with love2d-js (opens in a new tab), a LÖVE-style engine, and play them right in the page.

Find your way around a Linux shell: files, pipes, processes and small scripts.

Sorting, searching, graphs and dynamic programming: write the classic algorithms and measure how fast they run.

Draw pixels, lines and triangles yourself, then build up to a small 3D renderer.

Train models from data: regression, classification and small neural networks, built step by step.

Teach programs to see: filters, edges, features and recognising what is in an image.

How large language models work: tokens, embeddings, attention, and a tiny transformer you train yourself.

Build a computer from scratch: write a RISC-V CPU emulator, then a small Unix kernel that boots on it.