BBC News
By Jane Wakefield
image copyrightRoblox
David Baszucki, is about to become a very rich man, as his video-game platform, Roblox, floats on the New York Stock Exchange, valued at a cool $30bn (£21.6bn).
Already, he has bigger ambitions for the game, which he hopes can become the centre of the so-called Metaverse - an online world not just for gaming but for work and learning, too.
But what is the appeal of a title whose audience mainly consists of the under-12s?
And can its future lie beyond games?
Gaming marketplace
Roblox is already the world's largest user-generated games site. Players use core building components to create and share online worlds that anyone can explore.