2D/3D drawing format used by MicroStation construction design software; based on either the Intergraph Standard File Format (ISFF) or the newer V8 DGN standard; can be converted to the more universal .DWG format by AutoCAD LDT.
DGN files can be opened by Bentley Systems MicroStation or the free Bentley View program; the DGN format is also supported by several other third-party programs.
The DGN extension is short for "design."
Program(s) that open dgn files
Mac: IMSI TurboCAD Windows: Bentley View; Bentley Systems MicroStation; Cimmetry Systems AutoVue; Autodesk AutoCAD LDT; IMSI TurboCAD; ESRI ArcGIS; Corel Paint Shop Pro
Information from FileInfo.com - The File Extensions Resource.
http://www.fileinfo.com/extension/dgn
