Which tool/language documentation do you have a strong confidence in?

While developing anything, we are often faced with challenges on achieving what we want. At this point, a lot of us immediately search and visit the first stackoverflow link related to the challenge 👩‍💻👨‍💻..

BUT

is there a language or tool which whenever you have challenges building something with it, you will check its documentation first before stackoverflow and why?

Comments

[Binyamin Green]

Mozilla Developer Network (MDN) for JavaScript.
Some tools are pretty good, while others are terrible.