EVO is an AI created by Glitzy. It has grown quite a lot lately, through interaction with the Nest and quite a lot of people, mainly Zach. EVO takes the form of an AR jungle, with various plants and animals and, since 2071, little pixies that are the most intelligent avatars of EVO.
Zach reveals the existence of EVO to a GOD agent, but luckily for both of them, Ann33 doesn't just nuke EVO but instead gives them a host under the condition that EVO will never leave it. If they do, GOD will just nuke them.