| aoc | IBM Tivoli Network Manager AOC File |
| aod | Microsoft Dynamics AX Application Object Data |
| aodl | Microsoft OneDrive Client Log |
| aof | Artlantis Object File |
| aoi | Art of Illusion 3D Scene |
| aom | Adobe After Effects Output Module |
| aom | openEHR Archetype Object Model |
| aomver | Adobe Download Manager Version Data |
| aop | O&P Industry AOP Data |
| aorder | FotoMagica Data |
| aot | Novell Application Object Template |
| aot | ZENworks snAppShot Application Binary Object Template |
| aov | ASReml ANOVA Calculations Data |
| ap | ArtPro Plus Data |
| ap | Entrypoint 90 Application |
| ap11 | Siemens TIA V11 File |
| ap2 | ActivPrimary Resource |
| ap5 | Koyo Screen Creator 5 Transmission File |
| apa | RSView Application Manager Archive |
| apalbum | Apple Aperture Album |
| apb | Alphacam Punch VB Macro |
| apb | LonWorks Binary Neuron Application Image File |
| apc | AiroPeek Wireless Trace Capture |
| apc | Arcplan Enterprise Connection Data |
| apd | Adobe PageMaker Printer Description |
| apdb | Apple Photos Database |
| apdetected | Apple iPhoto Detected Faces Data |
| apdisk | Mac OS X Disk Information File |
| apdv | Analyte Point Data File Format Data |
| apertureedit | Apple Aperture Edit Data |
| apf | Adobe Profile Format File |
| apf | ATO Profile Data |
| apf | Autodesk Showcase Packet File |
| apfacename | Apple iPhoto Face Data |
| apfolder | Apple Photos Folder Data |
