Sandwich is a project to create low-cost electronics for 3D printing and CNC using an ATMEGA644p and TB6600 stepper drivers, not entirely unlike http://www.reprap.org/wiki/Gen7T and http://www.reprap.org/wiki/Sanguish.

The goal is to make an easily built, free and open design capable of running the Marlin firmware that can be built for around $40.

Design work is currently being done in the hobbyist-friendly Eagle CAD.
If the design exceeds the limits of the free version of Eagle CAD, the design will likely be ported to gEDA or another free CAD system in order to support the free and open design goal.