Betaville is a multi-person open source platform which allows participants to build on empty spaces in New York City, like a real-life version of the popular game Sim City.

Betaville is an open-source multiplayer environment for real cities, in which ideas for new works of public art, architecture, urban design, and development can be shared, discussed, tweaked, and brought to maturity in context, and with the kind of broad participation people take for granted in open source software development.
In this case, the proposal takes the form of a 3D model set in a "mirror world" of the local context, with a built-in discussion forum, and provision for multiple iterations... the environment can accept models from authoring tools as simple as Google Sketchup, or as elaborate as Autodesk Maya. Anyone with access to a web browser can contribute, and every contribution remains accessible.

Betaville website

Name: Betaville
Type: People
Urban trend: Forecasting
Status: Less active
Created by: Individuals and collectives
Created for: People
Works: Top-down
Accessibility: Low