http://unity3d.com/unity/
Astonished !

Hi Pilou,

Am I right that the free version displays a watermark?

Version without watermark appears to be US$1500.

Standalone games and iPhone games will not display the "Made with Unity" splash screen. Web player games will not display the 5 second Unity watermark.

Still an incredible app for free.

As a Unity user, I can say that is an AWESOME deal for folks who want to get into games development!

-Will

Well I'm sold! Thanks for the clarification guys. Another one to download.

Unreal is also free. It is more powerful than Unity but PC only.

Can be trees and plants exported as mesh objects (obj, 3ds, ?) from the free version?

I suppose yes :)
http://www.unifycommunity.com/wiki/index.php?title=ObjExporter

Based on ObjExporter.cs, this "wrapper" lets you export to .OBJ directly from the editor menu.

This should be put in your "Editor"-folder. Use by selecting the objects you want to export, and select
the appropriate menu item from "Custom->Export". Exported models are put in a folder called
"ExportedObj" in the root of your Unity-project. Textures should also be copied and placed in the
same folder. */

Sounds good. For 3D-PDF use a light vegetation can be very useful.

Thanks,
Micha