From time to time I find a dive into the Standford Encyclopedia of Philosophy useful for refreshing my memory on some ideas and concepts.
Also the MDN Learning Area is really useful for getting a handle on some web development details.
What others are you fond of, whether esoteric or exoteric*?
*
one of my other favorites is any sort of thesaurus that provides antonyms, 'cause some antonyms just aren’t as commonly used!
🤞 this federates properly this time (sorry if the old post eventually emerges, I initially posted this shortly after the Lemmy update kinda threw a wrench in things across instances)
https://www.openstreetmap.org/ – geography
https://www.orchidroots.com/ – official orchid names, and pictures
and the sister projects of Wikipedia, in particular:
https://en.wiktionary.org/ – dictionary
https://en.wikisource.org/ – old books (also in other languages)
https://en.wikivoyage.org/ – touristic information
https://species.wikimedia.org/ – species
You said “beyond Wikipedia”, but I will also mention that Wikipedia in other languages is an excellent resource to learn a language.