- Advent of Code: https://adventofcode.com
- Advent of SQL: https://adventofsql.com
- Advent of Cyber: https://tryhackme.com/r/christmas
- Advent of Chess: https://www.adventofchess.com
- Advent of Craft: https://github.com/advent-of-craft
- MATH+ Advent Calendar: https://www.mathekalender.de/wp
- Java Advent Calandar: https://www.javaadvent.com
- Advent of Rust: https://www.rustfinity.com/advent-of-rust
- Advent of CSS: https://www.adventofcss.com
- Advent of Javascript: https://www.adventofjs.com
- Advent JS: https://adventjs.dev
Summer Calandars
- Summer of Math Exposition: https://some.3b1b.co
Continuous Challenges
- Project Euler: https://projecteuler.net
- The Athenaion: https://www.the-athenaion.com
- Hannukkah of Data: https://hanukkah.bluebird.sh/5784
- Everybody Codes: https://everybody.codes/home
- Pi Day Contest: https://ivanr3d.com/projects/pi
- Rosalind: https://rosalind.info
- Protohackers: https://protohackers.com
- Cryptopals: https://cryptopals.com
- Deus x64: https://deusx64.ai