Dryad lets you intuitively create beautiful trees for your virtual world or game. In Dryad, you create a tree by visually navigating to it through a design space: the space of all trees. This space has close to a hundred dimensions and Dryad lets you move around it as if it were a city map. To help you find your way, Dryads around the world communicate to share which trees were picked in the past. A collaborative mapping of the tree space emerges, which your Dryad uses to gently steer you towards high-quality finds. We call this collaborative design space exploration.