Superstruct is the world’s first massively multiplayer forecasting game. By playing the game, you’ll help us chronicle the world of 2019--and imagine how we might solve the problems we'll face. Because this is about more than just envisioning the future. It’s about making the future, inventing new ways to organize the human race and augment our collective human potential.

...

Superstruct is played on forums, blogs, videos, wikis, and other familiar online spaces. We show you the world as it might look in 2019. You show us what it’s like to live there. Bring what you know and who you know, and we’ll all figure out how to make 2019 a world we want to live in.

(Link)

Superstruct is a project of the Palo Alto-based Institute For The Future.  If someone wants to try to bring seasteading into Superstruct, that would be awesome.