- This article is about the computer file format. For the Illinois high school, see Downers Grove North.
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.
- 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.