What is "cemu"

Cemu is a video game console emulator for the Wii U that runs on Windows. Created by two people, Exzap and Petergov, the first version, 1.00, was released on October 13, 2015 while the current version, 1.5.5, was released on August 15, 2016. Typically, Exzap updates the emulator once every two weeks. It is so far the only eight generation console emulator in existence since the PlayStation 4 and Xbox One were not reverse-engineered yet.