Well I wish I could help but one tip to create a virtual world is not for free! But Alice teachs computer programming plus it's 100% free! http://www.alice.org If you decide to download it click save when the box appears!
one website i know and love alot is wolfhome .com with virtual wolves that are 2d. lsstoon -- www.virtualwolfworld.webs.com
you go to google type in how you can make a virtual world
what are the 2d shapes of the real world
go onto youtube and type in (') how to make a virtual world website (') without the comas and brackets. then it may tell you
you can make one in my first world.
Using VastPark Creator.
sims 3
There are many different online virtual worlds, I like Habbo Hotel which is a 2d World where you can meet new people, earn credits (money) Sell things ect.. Its just like having a life on a computer ! Its Brill
You can create a virtual pet site at myvirtualpetsite.com You can customise your site/world to your tast.
Moviestarplanet
Yea! IAmFam is pretty good! And sims....
Try SmartFoxServer.