Advent of Code is an Advent calendar of small programming puzzles for a variety of skill sets and skill levels that can be solved in any programming language you like.
python3 DayXX/Python/main.py
gcc DayXX/C/main.c -o dayXX
./dayXX
tsc DayXX/TS/main.ts
node dayXX.js
g++ DayXX/CPP/main.cpp -o dayXX
./dayXX
php DayXX/Php/main.php