LEGO Digital Designer, or LDD, is a free computer program produced by the LEGO Group as a part of LEGO Design byME. It is available for Mac and Windows platforms. The program allows users to build models using virtual LEGO bricks, in a computer-aided design like manner. Until January 16, 2012, these could be uploaded, along with instructions and a box design, to the LEGO Design byME website, from where the models could be ordered for delivery as a real, packaged set. Users can also take "screenshots" of their models and store the models on their computer in an .LXF file.