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. A file format is a particular way to encode information for storage in a computer file. ... Bentley Systems, Incorporated, provides software for the lifecycle of the worlds infrastructure. ... MicroStation is the platform architectural and engineering software package developed by Bentley Systems, Incorporated. ... Intergraph was founded in 1969 as M&S Computing, Inc. ...

There are two versions of DGN:

• Up until 2000, all DGN files were based on the Intergraph Standard File Format (ISFF) specification, published in the late 1980s by Intergraph. Sometimes referred to as V7 DGN, or Intergraph DGN.

• In 2000, Bentley Systems created an updated version of DGN which includes a superset of DGN's capabilities, but which has a different internal data structure than the ISFF-based DGN. This version is properly referred to as V8 DGN.

Although DGN is not as widely-used as Autodesk's DWG, it is nevertheless mission critical in many large projects, including buildings, highways, bridges, process plants, shipbuilding. DWG (pronounced drawing) is the default extension used by Autodesk for its AutoCAD drawing files in MS-DOS and Windows. ...

Both versions of the DGN file format are documented by their developers, assuring owners of projects which use DGN that they will have long-term access to their design data. This is in contrast to DWG, which Autodesk has never documented, and early versions of which Autodesk no longer supports.

External links

• OpenDGN - Bentley's OpenDGN initiative
• Microstation 95/ISFF Description (pdf) - Information on the ISFF/DGN file format as distributed with Microstation 95.
• ISFF Specification - Intergraph Standard File Formats (Element Structure)
• DGNLib - DGNLib: a free Microstation DGN (ISFF) program library
• DGNdirect - DGNdirect, from Open Design Alliance: a V8/V7 DGN program library.