You usually generate a "toolpath" which is a set of instructions for the machine to follow. For old MakerBots this was .gcode (http://en.wikipedia.org/wiki/G-co

You usually generate a "toolpath" which is a set of instructions for the machine to follow. For old MakerBots this was .gcode (http://en.wikipedia.org/wiki/G-code http://en.wikipedia.org/wiki/G-code) which is the exact instructions to control the toolhead. It's a standard insomuch as XML is a standard, that is, format but not content is standardized. The pros use something like SolidWorks and STEP or IGES to export to CAM.