Главоблъсканици

http://www.pythonchallenge.com/	The first programming riddle on the net.
https://cmdchallenge.com/	Web application that presents small shell challenges.
http://guesshub.io/	GIT guessing game.
http://flexboxfroggy.com/	Help Froggy and friends by writing CSS code.
http://cssgridgarden.com/	Write CSS code to grow your carrot garden.
http://notpron.org/notpron/	The hardest riddle available on the ineternet.
https://vim-adventures.com/	Learning VIM while playing a game.
https://www.codewars.com/	Improve your skills by training with others on real code challenges.
https://www.root-me.org/	The fast, easy, and affordable way to train your hacking skills.
https://www.codingame.com/	The new way to improve your programming skills while having fun and getting noticed.