DGN
DGN (design) is the name used for CAD file formats supported by Bentley Systems' MicroStation and Intergraph's Interactive Graphics Design System (IGDS) CAD programs.
There are two versions of DGN:
The DGN format is used in many large projects, including buildings, highways, bridges, process plants, shipbuilding. DGN is a competing format to Autodesk's DWG.