Second Life - Second Life is a virtual reality platform where individuals interact in a virtual world. The software was developed in 2003 by Linden Labs. More than one million people now regularly use the software.
VRChat - Create and play in virtual worlds with others
Discovery Grid - A high-functioning alternative to Second Life, huge land parcels available for $30.00 per month.
ActiveWorlds - Activeworlds hosts a Universe of over 500 3D virtual reality worlds.
Vircadia - Vircadia is an open-source and decentralized real-time VR creation platform for university, enterprise, social, and OpenSim users.
Habbo - Hobbo is also known as ‘Hobbo Hotel’.