| novabackup | Nova Launcher Home Screen Backup |
| npac | NeoEngine Resource Package |
| npf | NTI Backup Now Partition File |
| nsarc | Neuro-MEP.NET Software Archive |
| nsk | NaShrinK Compressed Archive |
| ntj | Junction Box Backup |
| nuget | NuGet Package |
| nvz | Novelty Content Package |
| nxa | NanoTrader Nano Export Archive |
| nz | NanoZip Compressed Archive |
| oap | Bada Signed Installation Package |
| oap | OutSystems Application Package |
| oar | OpenSimulator Archive |
| oarc | Optix Archive Bundle |
| ob | ABF Outlook Backup Archive |
| ob3 | ABF Outlook Backup Archive |
| ob5 | TopLang OE Backup Data |
| obb | Android Opaque Binary Blob File |
| obml15 | Opera Mini Saved Web Page |
| obml16 | Opera Mini Saved Web Page |
| obr | OSGi Bundle Repository Data |
| ocb | Oxygen Forensic Detective Cloud Backup Archive |
| ocbx | Oxygen Forensic Detective Cloud Backup Archive |
| ocbx | Oxygen Forensic Detective Desktop Backup |
| odb | Oxygen Forensic Detective Desktop Backup |
| odmp | Optix Collection Package |
| odz | IBM OpenDoc Editor Package |
| oex | Opera Extension |
| ofb | Oxygen Forensic Suite Backup |
| ofbr | Oxygen Forensic Detective Important Data Backup |
