MoMAR - AR gallery within the MoMA + open source
VeeR VR - Global VR video community
Wanderlog Pinboard - A digital corkboard: map your and your friends' travels
GatherinVR by Queppelin - GatherInVR is a platform for VR meetings and VR conferences and can be customized for any business or company.
dropdrop - Leave messages where you travel for others to discover
VRChat - Create and play in virtual worlds with others