JavaScript with types: it catches mistakes before the code runs and makes large projects much easier to maintain. It is the language of this site, front and back.

The language of web browsers: it brings web pages to life and, with Node.js, runs on servers too.

Google's framework for full web applications, with components, routing and forms built in. This site's frontend is made with it.

A toolkit to build mobile apps with web technologies (HTML, CSS and JavaScript) and ship them to Android and iOS.

The world's most used mobile operating system, with its own tools for building native apps.

A runtime that runs JavaScript outside the browser, great for fast servers and APIs. It powers this site's backend.

A veteran web language behind a huge share of the world's websites.

An easy-to-read, very versatile language: automation, data science, artificial intelligence and much more.

High-performance languages close to the hardware, used in operating systems, games and embedded systems.

The markup language that gives every web page its structure.

CSS styles web pages (colors, layout, animation); SCSS (Sass) adds variables and reuse to keep large stylesheets tidy.

A free, open-source game engine for 2D and 3D games.

Microsoft's language for the .NET platform, used in business systems, desktop apps and games.

Boards and a programming environment that make electronics projects with sensors, LEDs and motors easy.

Microchip's family of microcontrollers, found in countless electronic devices.

A credit-card-sized computer that runs Linux — great for automation, home servers and hardware projects.

An inexpensive microcontroller with built-in Wi-Fi and Bluetooth, widely used in Internet of Things projects.

A numerical computing environment widely used in engineering for calculations, simulations and plots.

A free alternative to MATLAB, compatible with most of its scripts.

A language built for statistics and data analysis, with powerful charts.

Microsoft's spreadsheet — formulas, pivot tables and charts to organize and analyze data.

A robust, cross-platform language, widely used in enterprise systems and, for a long time, on Android.

Microsoft's relational database, common in businesses.

An open-source relational database known for reliability and advanced features.

A whole database in a single file, built into phones, browsers and millions of apps.

One of the most popular relational databases on the web — it stores this site's data.

A document (NoSQL) database that stores data in a JSON-like format.

Packages applications into containers that run the same on any machine. This site runs in containers.

Version control: it keeps the history of the code and lets many people work on it together.

Apache Subversion, a centralized version control system still found in many companies.

The open-source operating system that runs most of the world's servers — this site's included.

Google's platform with a ready-made database, authentication and hosting for web and mobile apps.

A CSS library with ready-made components to build responsive pages quickly.

A library for 3D graphics in the browser — this site's animated backgrounds use it.

A minimalist framework for building servers and APIs in Node.js.

A modular Node.js framework inspired by Angular. This site's backend is built with it.

A robust PHP framework behind many professional web systems.

An app for testing APIs: it builds requests and shows the responses.

A platform for testing, documenting and sharing APIs.

Meta's component-based UI library, one of the most used on the web.