Virtual worlds are picking up steam, with $345 million invested in them already this year, according to TechCrunch. 

Therefore, it seems only likely that one of the web's biggest names -- Google -- would enter the scene.

On Tuesday, the search giant unveiled Lively, a 3D virtual environment available to users completely free of charge.

Lively users can create their own avatars and build unique virtual rooms customized with pictures from Google's photo-sharing site, Picasa, and TVs that show YouTube videos. Up to 20 avatars can chat in a room at one time.

"We hope you will use the product to express yourself with and without words, and to do this in the places you already visit on the web," developer Niniane Wang wrote in a post on the official Google blog.

Wang developed Lively in her free time, but some of its features give it the potential to become one of the leading virtual worlds, according to The New York Times.

Unlike Second Life, a virtual world with hundreds of thousands of users, Lively is free and requires only a small software download. Users can also enter Lively through rooms embedded on websites and blogs they already visit, instead of being tied to one website like other virtual worlds.

Google currently has no plans to sell advertising on Lively.