TL;DR Installation 01 is a Halo fangame for Windows, Mac, and Linux. It aims to recreate classic Halo multiplayer. 343i has said they like the project. Ask me anything about i01, I'm a 3D Art Lead :) Note, one funny thing about that IGN article is their usage of the phrase "legally backed" we don't have a contract or license or anything, we just have open comms with them and a good relationship.