DXF (Drawing Exchange Format)
http://blumberger.net/wp-json/wp/v2/posts/136 AutoCAD DXF (Drawing Exchange Format) is a CAD data file format developed by Autodesk for enabling data interoperability between AutoCAD and other programs.
http://fidelity-energy.co.uk/consultancy/ DXF was originally introduced in December 1982 as part of AutoCAD 1.0, and was intended to provide an exact representation of the data in the AutoCAD native file format, DWG (Drawing), for which Autodesk for many years did not publish specifications. Because of this, correct imports of DXF files have been difficult. Autodesk now publishes the DXF specifications on its website for versions of DXF dating from AutoCAD Release 13 to AutoCAD 2010.