Discreet Render Format (DRF) file created by VIZ Render, a program included with older versions of Autodesk Architecture; saves a rendered image of buildings or other modeled structures; can be opened in 3ds Max, but can only be created by VIZ Render. After opening a DRF file in 3ds Max, you must save it as a .MAX file since saving DRF files is not supported.
Data file created by Dynojet vehicle diagnostics tools; saves car information from a diagnostics test; may store horse power, air temperature, humidity, absolute pressure, and vehicle model data; used for graphing vehicle diagnostics information. DRF files can be viewed using WinPEP (Windows Performance Evaluation Program), which was formerly called the Dynojet RunViewer.
Temporary file created by Delphi, a software development programming language and IDE; saves package requirement information when a project is compiled with packages; used during the software building process. DRF files are sometimes referenced in Delphi error messages when a program cannot located or create the file in a temporary location. To fix this, you may be able to explicitly rebuild the application or make sure the temporary location is accessible.