Land Surveyors: free Contouring program

SiteTopo is a free contouring program for Land Surveyors.

Loads survey point files, or DXF and XML formats.

Works with plain AutoCAD (no addons needed), and makes no changes to
your CAD setup.

* Digital Terrain Modeling for generating Contours from your survey
points.
* 3D view lets you see your survey from any perspective.
* Features such as contours are updated automatically anytime the
surface changes.
* Includes raining and ponding simulation.
* Overlay CAD image onto surface.
* Add Breaklines to surface just by clicking on points.
* Cut Sections through surface and ex****t.
* No installation, standalone executable.
* Currently, it is Free!

Download it: http://www.sitetopo.com/

Flash movie of the program in action:
http://www.sitetopo.com/flash/demo1/demo1.html