Kitely is described as 'enhanced OpenSim metaverse of virtual worlds. Graphically superior, and the world you create is portable and can be backed up locally to your machine!' and is an app in the Social & Communications category. There are six alternatives to Kitely for a variety of platforms, including Windows, Online / Web-based, Mac, Oculus Rift and Linux. The best alternative is Second Life, which is free. Other great apps like Kitely are Hubs by Mozilla (Free, Open Source), STAGE by vr-on (Freemium, Open Source), Facebook Horizon (Free) and OpenSimWorld (Free).
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).
STAGE Cloud enables Unreal and Unity Enterprise professionals to instantly create, deploy and use their multi-user VR applications. STAGE Cloud requires only 3 simple steps to roll out multi-user VR applications. Further details: www.vr-on.cloud.
In Facebook Horizon, not only can you explore the virtual world as it grows and changes, but you can discover all sorts of new things that interest and inspire you. Experience gravity defying, distance spanning, genre bending games of all types.
Discovery Grid is an Opensim-based virtual world. It operates much as Second Life does. Some of it's outstanding features are: Extremely low lag, large land masses available (up to the equiv of 64 SL sims!