Introduction and Download
OpenSCAD is available to download (for PC, Mac and Linux) from here.
The source code is also available from the above link, so if you have a C-compiler, then you may be able to use it on other platforms.
http://www.openscad.org/about.html
OpenSCAD can be used for generating 2D DXF files for use on the Dyson Centre laser cutters, for example; or 3D STL files for use on the Dyson Centre 3D printers, for example.
Tutorials, Cheatsheet and Range of Commands
A very handy cheatsheet / quick reference sheet is available here.
Full documentation and other resources, such as tutorials are available here.
Example 2D file for use on the Laser Cutters
Click here to download example *.SCAD file shown below.