There are Unity3D packages available to add Photon multi-user networking support and IMVU avatar connections.
Photon Realtime multiplayer networking support is available using their Photo Cloud free for up to 20 concurrent users, or you can host a Photon MMO server yourself. You need to register (free) for a Photon Realtime App ID to complete the configuration needed in Unity3D.
IMVU is a 3D avatar -based chat and social platform with millions of users. A Unity package provides a means to load an IMVU avatar, and that of your friends, into Unity, and synchronize communication using multi-player support from Photon or Unity Networking. You need to register (free) for an IMVU avatar (unless you already have one) and a developer App ID to complete the configuration needed in Unity3D.
- Unity Asset Store: IMVU API for Unity (with Photon support)
- Unity Asset Store: IMVU API for Unity (For UNet – Unity Networking)
Once the Photon Networking and IMVU Unity packages are installed in a Unity3D project you can open the various Photon and IMVU demonstrations to see how things work.
I have begun to experiment with a Unity application based on these packages to allow for multi-user support in an OpenVCE collaboration environment.