A free, no-install guide that shows how to set up and use popular programming languages.

Languages: Python, JavaScript, Rust, C, C++, Java, Go and Assembly (x86-64, NASM).

Every language has the same eight short lessons, so you can learn one language or compare them side by side:

1. Setup & run
2. Hello, World
3. Variables & types
4. Control flow
5. Functions
6. Collections
7. Error handling
8. Key idea

• Runs entirely in the browser. No build step, no server, no account.
• Search across all lessons (press / to focus the search box).
• Compare view: see the same topic in every language at once.
• One-click copy buttons on every code block.
• Light and dark theme.
• Works on phones.

Open index.html in any modern browser. That's it.

To host it for free, enable GitHub Pages in the repository settings (Settings, Pages, deploy from the main branch, root folder).

index.html          page shell
css/style.css       all styling
js/app.js           routing, search, compare view, theme
js/data/*.js        one file per language (the lessons live here)

1. Copy any file in js/data/ (for example go.js) to a new file such as js/data/kotlin.js.
2. Change the id, name, color, ext, comment, keyword lists and the eight topics.
3. Add a <script src="js/data/kotlin.js"></script> line to index.html, before js/app.js.

The order field decides where the language appears in the sidebar.

Found a mistake, or want another language or topic? Open an issue or a pull request. Please keep examples short and make sure they run.