I was always interested in Virtual Worlds but could never find any major game engine for it. My quest for finding Virtual Worlds game engine started with Adobe Director.
My curiosity led me to ask a question on LinkedIn Group – Virtual Worlds and if anyone knew of more game engines than Director. I was really amazed by the reponse I received and it prompted me to write this post on my blog.
The choice of Virtual Worlds game engine depends upon your project, resources, budget, genre and platform.
Unity 3D
It is currently one of the more popular Virtual Worlds Game engine.
Unity is a multiplatform game development tool, designed from the start to ease creation. A fully integrated professional application that just happens to contain the most powerful engine this side of a million dollars.It was available for MAC only but is soon going to come on PC and I hope releasing on PC will only add to its popularity.
Unity 3D contains everything available for an actual 3D game engine and much more. It has an Integrated Editor, Asset importing, Shaders, Terrains , Scripting, Physics, lighting and also has features for Iphone and Wii publishing.
For a full list of features please visit: http://unity3d.com/unity/features/.
An online fashion game created with Unity 3D – Frenzoo


Tropical Paradise from Unity 3d
Project Darkstar
Project Darkstar is software infrastructure that aims to simplify the development and operation of massively scalable online games, virtual worlds, and social networking applications. Originally created by Sun Microsystems, it is today advanced as an open source project through the Project Darkstar Community.
Project Darkstar is designed to help developers and operators avoid a range of serious, yet typical, problems associated with massive scale online games today, including zone overloading, data corruption, and server under-utilization. In addition, Project Darkstar will enable developers to support new dimensions of play such as evolvable virtual worlds and very large scale battlefields.
Project Darkstar is designed to be used directly by developers and operators of massively scalable online games, virtual worlds, and social networking applications. Indirectly, Project Darkstar may also serve publishers of these applications, to whom development and operational time and cost savings are often transferred.

Project Darkstar
Realxtend
It’s an opensource engine made from OpenSim and Ogre 3D. RealXtend offers a free open source virtual world platform with which you can create your own applications using it as a base.The realXtend viewer is an open source browser (GPL license) that you can use to experience rich multiuser virtual worlds.
The realXtend server is an open source server (BSD license) with which you can make your own virtual worlds available to a larger audience. The server has a sample virtual world that you can utilize as it is or you can modify it to suit your needs. realXtend also offers free, high-quality content for your own worlds.

OpenSpace
OpenSpace is a powerful Flash based isometric engine and framework for rapid development of multi-user virtual worlds and MMO communities.The engine leverages the power of ActionScript 3 and SmartFoxServer, offering an unprecedented level of features and customizations.

Openspace
Qubesoft
Q is a new middleware for games and other real-time 3D applications .Q’s framework allows developers to rapidly specialize the middleware to address their specific needs by adding custom plug-ins at any level. Standard plug-ins can be mixed and matched with a developer’s own plug-ins, making it easy, for instance, to add a custom scene management plug-in which both takes advantage of game specific knowledge, and also builds on standard components to stream its assets.
As well as a host of standard engine features, Q sports cutting-edge capabilities rarely found in bespoke high end game engines; and these are supported on all platforms, console and PC:
* A powerful renderer supporting arbitrary scene rendering algorithms and programmable shaders
* Background data streaming
* A texture manager capable of handling scenes with many gigabytes of texture visible on screen
* A cross-platform data format
* Simultaneous n-dimensional animation blending
* A background work queue
* A 3D editor which allows both core and custom plug-ins to run live inside the editing environment

Drupal
Drupal is a free software package that allows an individual or a community of users to easily publish, manage and organize a wide variety of content on a website. Tens of thousands of people and organizations are using Drupal to power scores of different web sites, including
* Community web portals
* Discussion sites
* Corporate web sites
* Intranet applications
* Personal web sites or blogs
* Aficionado sites
* E-commerce applications
* Resource directories
* Social Networking sites
TheOWorlds
They are an interactive web agency with a focus on Flash games, e-cards and online virtual worlds.They specialize in creating highly engaging and entertaining online experiences that can help our clients deliver their message in a new and original way! If you are looking into viral marketing tools for your business.
MetaMole: It is like a search engine for Virtual worlds. If you can’t it anywhere, you will surely find it here.