Interactive coding screencasts you can edit and run.
Learn to code listings
Free coding practice across dozens of languages with mentoring.
Learn back-end development through a game-like course.
Learn by building your own Redis, Git, and other tools.
Text-based interactive courses for developers.
Cards

Scrimba
scrimba.com
Scrimba
Interactive coding screencasts you can edit and run.

Exercism
exercism.org
Exercism
Free coding practice across dozens of languages with mentoring.

Boot.dev
boot.dev
Boot.dev
Learn back-end development through a game-like course.

CodeCrafters
codecrafters.io
CodeCrafters
Learn by building your own Redis, Git, and other tools.
Educative
educative.io
Educative
Text-based interactive courses for developers.