99% Bryce 5. - Everything is pure Bryce, except for the grass that was done with a free program that I found the other day. Here is some information from the Bantam3D site (Note - this site has now vanished and it appears that the software is no longer available)

Bantam3D Grass is a software application that generates 3-dimensional ground covers such as grass, leaves, and rocks.

Working with a very simple, intuitive interface, you can create realistic grass or leaves or rocks in just a few minutes. The grass is an object of .obj file format, which can be imported to any 3D applications such as Bryce, Vue, and Poser for rendering.

You can define the curves of the grass blades, as well as their shape, size, rotation, how many blades are going to be grouped together, and how many blades are going to be twisted.