Second Life

second life is a free 3d virtual world where users can socialize, connect and create using free voice and text chat. to access this world you need to use a viewer such as second life viewer (see second life viewer).

Freemium Mac OS X Windows Linux Web

ActiveWorlds

Activeworlds hosts a Universe of over 500 3D virtual reality worlds. In these worlds you can choose from a vast array of avatars that fit your personality (or your perceived personality - that's half the fun!).

Free Mac OS X Windows Linux

IMVU

A 3D internet chatroom application for chatting with friends and meeting new people

Freemium Windows

Vicarious VR

Vicarious is a social platform that lets you share and discover stories through an immersive experience accessible in 2D and 3D in virtual reality.

Free Android Daydream