Sprog is a graphical tool that anyone can use to build programs by plugging parts together. In Sprog jargon, the parts are known as 'gears' and they are assembled to make a 'machine'. Gears are selected from a palette and dragged onto the Sprog workbench, where they can be connected together. Options can be set using a properties dialog on each gear. When assembly is complete, the machine can be run, reconfigured, or re-run.