SF-based Rocketon, a developer of a web-based virtual world and gaming service, has raised a $5 million second round from DE Shaw Group’s venture unit. The company previously raised $800,000, bringing its total to $5.8 million. The service is still closed, so it’s difficult to know exactly what they’re aiming for here, though the announcement positions the company as some sort of MMPORG spin on social networking. It also suggests that its distributed somehow across multiple sites, though again, it’s not very clear..