All courses

Eleven tracks. Every one starts from absolute zero — what a program is, what a variable is — and builds to advanced and expert material. Lessons live in data files, easy to extend.

HTML

The structure of every web page.

Start from zero: what a document is, how tags work, and how to build real pages with headings, links, images, and forms.

12h · 3 lessons0%

CSS

Make pages readable and beautiful.

From zero: selectors, the box model, and layout. Style real pages and see changes instantly.

14h · 3 lessons0%

JavaScript

Make pages interactive and think in code.

From zero: variables, loops, functions. Run everything in the browser.

25h · 3 lessons0%

Python

Readable code for everything.

From zero: variables, loops, functions. Runs in your browser with Pyodide.

25h · 3 lessons0%

Java

Strict, reliable, everywhere.

From zero: what a class is, variables with types, loops, methods. Runs via the execution backend.

30h · 3 lessons0%

C++

Fast, close to the metal.

From zero: programs, variables, loops, functions. Runs via the execution backend.

30h · 3 lessons0%

C#

Clean syntax for apps and games.

From zero: programs, variables, loops, methods. Runs via the execution backend.

28h · 3 lessons0%

.NET (ASP.NET Core)

Build real web APIs with C#.

From zero: what a server is, minimal APIs, routing. Console examples run in the playground; web concepts are explained with runnable C#.

30h · 3 lessons0%

SQL

Ask questions of data.

From zero: tables, SELECT, filtering, sorting. Runs in-browser.

18h · 3 lessons0%

Git

Save work and collaborate safely.

From zero: repos, commits, branches. A guided simulator runs in the browser.

8h · 3 lessons0%

Data Structures & Algorithms

Think clearly about data and steps.

From zero: arrays, loops as counting, Big-O intuition, and your first sorts. Runnable JavaScript.

35h · 3 lessons0%