| msg | SOBEK Communications Data |
| msg | SmartWare Intro Display Data |
| msg5 | Microsoft Graph 5 Data |
| msgr | Microsoft Graph 5 Data |
| msgstore | WhatsApp Saved Chat History |
| msh | Orbiter 3D Mesh Data |
| msh | ANSYS Workbench Mesh Data |
| msh1xml | Windows PowerShell XML Data |
| msh2xml | Windows PowerShell XML Data |
| mshdb | Ministry Scheduler Pro Database |
| msie | Internet Explorer Related Data |
| msif | MyLabel Designer Deluxe Data |
| msj | MicroSurvey CAD Temporary Data |
| msk | BrainVoyager QX Mask Data |
| msk | Affymetrix Mask File |
| mskin | Maxthon Browser Skin |
| mskn | MediaMonkey Skin |
| msl | ImageMagick Script Language Data |
| msmpl_all | Korg microSAMPLER Backup Data |
| msmt | WNCS Measurement Data |
| msnbak | MSN Mail Backup Data |
| mso | Microsoft Office Rendering Data |
| msof | Microsoft Office for Mac Data |
| msor | FiberTrace Data |
| mspdi | Microsoft Project XML Data Interchange File |
| mspj | Microsoft Project for Mac Data |
| mspm | Nanoeducator File |
| msq | LightShow Pro Media Sequence |
| msr | Mail.dat Manifest Summary File |
| mss | Microprocessor Software Specification |