Intergraph Standard File Formats

Intergraph Standard File Formats (ISFF) are the file formats common to MicroStation and Intergraph's Interactive Graphics Design System (IGDS). ISFF is made available to the public, so that third-party developers could create applications for MicroStation that read and write ISFF format without a license from Intergraph.

Design files, or DGN files (*.dgn) are binary files with variable-length records for graphic elements, and non-graphic data.

Cell library files (*.cel) are binary files that store cell definitions for placement in design files.

Unfortunately, Autodesk has chosen not to support this public format in AutoCAD(2004).