Kattis

Kattis helps companies make safer recruitments and attract the best developers with its dynamic challenge platform. With Kattis companies make sure developers make...

Commercial Web

Codeeval

CodeEval is platform for hosting coding challenges which has over 20,000+ competitive developers.

Free Web

Geektastic

Unique peer-reviewed code challenges for deep insight into candidate's technical skills and abilities.

Commercial Windows iPhone Chrome OS

Screeps

Learn to code JavaScript by playing game. This game claims to be the world’s first MMO strategy sandbox game for programmers.

Commercial

Ruby Warrior

This version of Ruby Warrior is a project by Bloc, a part-time online coding bootcamp for people who want to keep their current job, learn how to code, and become a...

Free Personal Web

BerryBots

A simple robot game where you can program both the stage and the robot in Lua.

Free Open Source Mac OS X Windows Linux Raspberry Pi