Our current work relies on VRChat, a free Unity 3D multiuser platform.
You'll need Steam, SteamVR, and VRChat. Steam and VRChat also ask you to create accounts.

You do not need an Oculus Rift or Vive HMD.
A good PC will likely be just fine.
There is no Mac software.

Steam, SteamVR, and VRChat Update REGULARLY!
If coming to an event, please check ahead / give time to install)
... If you are meeting with Dr. Guynup, shoot him an email if you have a problem.