| abw | AbiWord Document |
| ac3d | AC3D Model |
| ac5 | ArtCut 5 Document |
| ac6 | ArtCut 6 Document |
| accd | Microsoft Access 2007 Database |
| accdb | Microsoft Access 2007 Database |
| accdc | Microsoft Access 2007 Signed Package |
| accde | Microsoft Access 2007 Executable |
| accdr | Microsoft Access 2007 Run-time |
| accdt | Microsoft Access 2007 Database Template |
| accdw | Microsoft Access 2007 Database Link |
| accfl | Microsoft Access Field Template |
| accft | Microsoft Access 2007 Data Type Template |
| adb | Ability Database Document |
| add | Alphacam Diecut Drawing |
| ade | Microsoft Access Project Extension |
| adoc | AsciiDoc File |
| adsk | Autodesk Exchange File |
| ae | SoftQuad Author/Editor Document |
| aed | Alphacam Wire EDM Drawing |
| af2 | Micrografx ABC FlowCharter 2 Document |
| af3 | Micrografx ABC FlowCharter 3 Document |
| afd | Alphacam Flame Drawing |
| afdesign | Affinity Design Document |
| aff | BART Animated File Format |
| agn | Psion Series 3 Agenda Document |
| agp | Aspen Graphics Workspace |
| agz | AggFlow Aggregate Plant Flow Diagram |
| aht | AH Note Text Document |
| aib | ArcInfo Binary Coverage |
