| Abbreviation | Definition |
|---|---|
| OBD | Binder (MS Binder) |
| OBJ | Compiled machine language code (Intel Relocatable Object Module) |
| OBJ | Object (Wavefront) |
| OBR | Object browser data file (Borland C++) |
| OBS | ObjectScripT Script FILE |
| OBS | ObjectScripT Script FILE |
| OBT | Template (MS Binder) |
| OBV | Visual interface (ObjectScript) |
| OBZ | Wizard (MS Binder) |
| OCF | Object Craft File |
| OCR | FAXGrapper Incoming FAX transcribed to text |
| OCT | Octalizer Musical file |
| OCX | OLE custom control (Object Linking and Embedding) |
| ODA | ODA document |
| ODA | Raster graphics (CALS Group IV Type 2) |
| ODF | Open Document Format (Open Office.org) |
| ODIF | Open Document Interchange Format |
| ODL | Object Definition Language file (MS Developer Studio) |
| ODT | Open Document Text |
| OFD | Form definition (ObjectView) |