Autodesk sales. It was sold directly by Autodesk Artlantis Studio 6 license in AhtoCAD stores unlike the full version of AutoCAD, which must AutoCAD Civil 3D 2018 mac purchased from official Autodesk dealers. Might we suggest coffee not included? History of CAD software. Several vendors provide online conversions for free such as Cometdocs. The native file format of AutoCAD is. Subscribe now. Thank you. See subscription benefits Includes support and more. Get more tips for successful downloading.