Learning programming can be fun and gamified

https://codefights.com/home
An online programming tournament environment where you can solve challenges in a single player, head-to-head or tournament mode


http://rosalind.info/problems/locations/
Rosalind is a platform for learning bioinformatics and programming through problem solving


https://projecteuler.net/
Project Euler is a series of challenging mathematical/computer programming problems that will require more than just mathematical insights to solve