Lively doesn't have money like its online rival Second Life
Google has launched a new 3D application that lets users build their own virtual fantasy worlds and interact with friends online.
The free software, called Lively, is similar at first glance to the web's 3D social environment, Second Life.
Users can create their own virtual characters, or avatars, and build land and accommodation from simple flats and ranches to exotic islands.
Rooms can also be decorated with YouTube videos or other online content.
Google's engineering manager Niniane Wang said: "If you enter a Lively room embedded on your favourite blog or website, you can immediately get a sense of the room creator's interests, just by looking at the furniture and environment they chose.
"You can also express your own personality by customising your avatar's look, and you can chat with each other, and you can also interact through animated actions."
The 3D world is the latest example of Google's expansion beyond its traditional search business.
The company's range now includes blogs, maps, 3D earth software, photo-sharing, spreadsheets and word processing.
So far, the applications have proved popular but not very profitable compared with Google's money-spinning search engine.
Google has no plans to sell advertising on its 3D world at the moment but bosses reckon that keeping users on the site for longer will ultimately lead to more moneymaking clicks on its search engine.
Lively does not require membership and, unlike Second Life, allows users to take their creations elsewhere on the web.
A plug-in application has already been designed for Facebook and developers are working on a MySpace version.
But, for all Google's influence, it might have a hard time prising users away from Second Life, which has been running for the last five years and is thought to have more than 12 million active users.
Lively is designed to be easier to use than its rival but, for the moment at least, it is less customisable.
Unlike Second Life, users cannot build their own furniture and clothes and must select from a predesigned range.
Lively is only available on Windows machines at launch although Google says a Mac OS X client is in the works.