Basis
Basis https://github.com/dooly123/Basis "provides you with all the necessary tools to create your own Social VR Platform to use as a Ready-To-Use Foundation to be built upon." While there is no release bundle available yet, its repository can already be used as a base or to add to VR Projects.
Built on Unity 6, this is basically a framework to serve as a base for a VRC type game rather than a full game. It is MIT Licensed.
Currently weekly to bi-weekly multiplayer test sessions are organized in their discord. These use a pre-compiled built of Basis to gather feedback and are open to anyone.