| cmpd | Chemnum Compounds Data |
| cmphs | CET Designer Photo Series Data |
| cmpkg | Chat Mapper Package |
| cmpkg | Craftersmine Packager Package |
| cmplib | Altium Designer Component Library |
| cmpm | NucleoView Plot Manager Data |
| cmpp | NucleoView Post Processing Data |
| cmppr | CET Designer Paper View Papers Data |
| cmpreset | CET Designer Photograph Setup Preset Data |
| cmpri | CET Designer Project Info |
| cmpt | Cesium Composite Tile Data |
| cmr | Coach Results File |
| cmrbk | CaseMap ReportBook Definition Data |
| cmrcf | CET Designer Reconfig Data |
| cmrf | CET Designer Families Data |
| cmrt | Conflict Minerals Reporting Template |
| cms | CaseMap Case Script |
| cms | TrialDirector Case Data |
| cmscl | CET Designer Schemes Data |
| cmsg | ArchiveOne CMSG Data |
| cmstl | CET Designer Text Styles Data |
| cmsup | NucleoView Package |
| cmsx | NucleoView Protocol Data |
| cmt | E-Sword v8 Commentary Data |
| cmtx | CrystalMaker Drawing Data |
| cmtx | E-Sword v9 Commentary Data |
| cmv | PBD-14 Circumferential Mean Velocity Data |
| cmw | Custom Maintenance Wizard Data |
| cmxl | Microsoft Pivot Collection Data |
| cmy | CorelDRAW Custom CMY Data |
| cmz | Poser Compressed Camera Data |
| cn | GenePattern Copy Number Data |
| cn | RMCProfile Nitrogen Carbon Neighbours Data |
| cnb | Pegasus Mail Noticeboard Message |
| cnc | QuickCAM Pro CNC Machine Tool Path |
