Dynamo for Vasari

Dynamo is a project started by Ian Keough to provide a code playground for building interesting parametric functionality on top of that already offered by Vasari, and to do so with a graphical interface that allows you to share your work with others less inclined to write code themselves.

Autodesk has extended the open source effort by adding some additional nodes and packaged it in an installer for Vasari to make it easier to get up and running.

There's more information on this WikiHelp page.