p5.js - https://p5js.org/
Javascript based creative programming environment
Processing - https://processing.org/
Java based visual programming environment
Sonic-Pi - https://sonic-pi.net/
Live-coding music in Ruby
Glitch - https://glitch.com/
Community for discovering and sharing code and projects. Maybe some educational tools here...
Fluxus - http://www.pawfal.org/fluxus/
Live-coding environment for making visual art/motion graphics. I just found this and it looked cool... Have no idea if it's decent.
Free Code Camp - https://www.freecodecamp.org/
Free resources to learn to code. Last time I checked it was project-based and more focused on practical learning over computer science theory.
Code Academy - https://www.codecademy.com/
Browser based code tutorials
Learn JS - https://www.learn-js.org/
Another browser based coding tutorial for JavaScript (Not sure if any good)
Classic book from the academic computer science canon. Might be throwing yourself in the deep end with this but it might be fun to do at some point. I'd be down to do it too since I've only done the first chapter. Here's an interactive version https://xuanji.appspot.com/isicp/
HackerRank - https://www.hackerrank.com/
Coding challenges in the browser. Lots of companies use these to screen applicants but you could use the problems to practice a language.
REPL.it - https://repl.it/
Try out any language in the browser. Useful for prototyping or messing around.
Hacker News - https://news.ycombinator.com/
Popular news/discussion site for programmers/tech-entrepreneur types. Lots of interesting content and discussions here and a good place to absorb programming culture.
What is Code? - https://www.bloomberg.com/graphics/2015-paul-ford-what-is-code/
Long-form Essay for a general audience about the role code plays in the modern world.