wordsandbuttons.online
This is the source code for Words and Buttons Online — a growing collection of interactive tutorials, guides, and quizzes about things generally considered boring. Maths, algorithms, programming languages.
See: https://wordsandbuttons.online/
Some examples of interactive pieces are:
https://wordsandbuttons.online/mathematical_analysis_explained_with_python_blood_and_tnt.html
https://wordsandbuttons.online/challenge_your_performance_intuition_with_cpp_magic_squares.html
https://wordsandbuttons.online/learn_you_a_lisp_in_0_minutes.html
All the code is properly unlicensed.