Lesson workspace

Web browser

The app displaying this lesson, such as Edge, Chrome, Firefox or Safari.

What it is for

All our interactive reading, quizzes and web exercises start here. No terminal is needed for an in-page example.

Install it

Use a current browser. You already have one open to read this page.

Official setup instructions ↗

Open it

Open a lesson on ClassAntics. Scroll to its editable example or demonstration.

Check it is installed — then verify

Where · This lesson · in your browser

Use the controls on this page. No terminal or installation is needed. Tool guide

Open a lesson and expand its editable example.

What you should see: The editor opens. If a live exercise is available, its Run button displays output in the page.

Try one small thing

Where · This lesson · in your browser

Use the controls on this page. No terminal or installation is needed. Tool guide

Change one value in the lesson’s editable code box and select Run or Preview there.

What you should see: The result appears below the code box. C# and Java downloads run on your computer instead; their in-page walkthroughs show expected output.

If something looks different

Scripts disabled: reading and setup guides remain available, but interactive exercises need JavaScript.
A C# or Java example does not have an in-page Run button: use the download and local setup instructions.

Lessons using this tool

Some use it only for optional local practice. Each lesson explains what you actually need.

JavaScript · 36 lessons

C# · 61 lessons

Java · 41 lessons

React · 31 lessons

HTML · 16 lessons

CSS · 21 lessons

SOLID · 5 lessons

Design patterns · 23 lessons

Official help

MDN: browser developer tools ↗

Guide reviewed 2026-09-09. Menu labels can differ between versions.