| mrex | Macrium Reflect Exchange Backup |
| mrimg | Macrium Reflect Disk Image |
| mrsql | Macrium Reflect SQL Backup |
| msi | Microsoft Windows Installer Package |
| msix | MSIX Package |
| msixbundle | MSIX Bundle Package |
| msm | Microsoft Windows Merge Module |
| msp | Microsoft Windows Installer Patch |
| msu | Microsoft Windows Vista Update Package |
| mva | Matrox Setup Program Archive |
| myc | Simply Safe Backup Archive |
| mzf | MediaZip Compressed Archive |
| mzz | Microsoft .NET Download Package |
| narc | Nintendo DS Archive |
| nba | Nero BackItUp Backup Archive |
| nbf | NTI Backup Now Archive |
| nbp | ArcSoft Totalmedia Backup Archive |
| nbz | ArcSoft Totalmedia Backup Archive |
| nca | Switch Nintendo Content Archive |
| nfp | Nokia Flash Package |
| nhn | ijji REACTOR Game Package |
| npf | NTI Backup Now Partition File |
| nsk | NaShrinK Compressed Archive |
| nuget | NuGet Package |
| nvz | Novelty Content Package |
| nxa | NanoTrader Nano Export Archive |
| nz | NanoZip Compressed Archive |
| oap | Bada Signed Installation Package |
| oar | OpenSimulator Archive |
| ob | ABF Outlook Backup Archive |
| obb | Android Opaque Binary Blob File |
| obml15 | Opera Mini Saved Web Page |
| obml16 | Opera Mini Saved Web Page |
| oex | Opera Extension |
| ofb | Oxygen Forensic Suite Backup |