Habbo!

ROBLOX is an online virtual playground and workshop - where kids of all ages can safely interact, create, have fun, and learn.

Manyland is an open universe we invent and live together. In an infinite, shared world of abundance, we create new things by drawing them, build new places of any kind, hang out and chat, throw around stuff, shape our own appearances, collect what we like and provide what's needed, make music, party, go swim, enjoy, jump n' run, take care of the world, do sports, come up with puzzles, explore... and have a lot of fun together in ways none of us can predict.

Miitomo is an app from Nintendo that brings out a side of you your friends have never seen before!

Build multiuser 3d scenes using html-like tags and javascript. SceneVR scenes are viewed using a browser-powered viewer (powered by webGL). Chrome, firefox and IE are supported. The server is powered by node.js and runs on Windows, Mac OS and Linux.

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!). You can then move about, play online games, shop and make friends with people from all over the planet. You can even stake claim to a piece of land and build your own virtual home, mansion, estate or castle! If you like to travel, there is plenty to explore.

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

Smeet is a virtual 3D World, where you can create your Avatar and your own Room. Start now and meet new friends, flirt, organize your party, share pictures and videos!

vSide is an immersive, interconnected virtual city environment where you can hang out, listen to music, chat, dance, and make friends.