| cmf | CIFMIF File |
| cmfav | CET Designer Favorites Data |
| cmfrl | CET Designer Furniture Layout Data |
| cmh | PLINK Cochran Mantel Haenszel 2x2xK Test Report |
| cmh2 | PLINK Cochran Mantel Haenszel IxJxK Test Report |
| cmj | ControlMyJoystick Profile |
| cml | Chemical Markup Language File |
| cml | CryptoMailer Encrypted File |
| cmlock | CET Designer Lock Data |
| cmm | Corel Multimedia Manager v7 Album |
| cmmtheme | CleanMyMac Theme Data |
| cmn | Microsoft SMS Collection Membership Update |
| cmod | Celestia Model |
| cmp | General CADD Component Data |
| cmp | Heliosoft Seismaster Colormap File |
| cmp | KiCad Parts-to-module Assignments Data |
| cmp7 | Araxis Merge Comparison Data |
| cmpck | CET Designer Pack and Go Data |
| cmpd | Chemnum Compounds Data |
| cmplib | Altium Designer Component Library |
| cmppr | CET Designer Paper View Papers Data |
| cmpt | Cesium Composite Tile Data |
| cmr | Coach Results File |
| cmrbk | CaseMap ReportBook Definition Data |
| cmrf | CET Designer Families Data |
| cmrt | Conflict Minerals Reporting Template |
| cmt | E-Sword v8 Commentary Data |
| cmtx | E-Sword v9 Commentary Data |
| cmw | Custom Maintenance Wizard Data |
| cmxl | Microsoft Pivot Collection Data |
| cmz | Poser Compressed Camera Data |
| cn | RMCProfile Nitrogen Carbon Neighbours Data |
| cn | GenePattern Copy Number Data |
| cnb | Pegasus Mail Noticeboard Message |
| cnc | QuickCAM Pro CNC Machine Tool Path |