| cwe | Crossword Express Document |
| cwf | CorelDraw Workspace |
| cwgr | ClarisWorks Drawing Document |
| cwk | ClarisWorks Document |
| cwn | Cifraweb Editor Notation Document |
| cwpt | ClarisWorks Painting Drawing |
| cws | ClarisWorks Template |
| cws | ChordWizard Songtrix Song |
| cwss | ClarisWorks Spreadsheet Document |
| cwt | ClarisWorks Texture |
| cww | CU-Writer Document |
| cwz | Circuit Wizard Document |
| cxbml | BML W5 Model |
| cxl | Content Extraction Language Document |
| cxscript | Celtx Script Document |
| cxt | Adobe Director Protected Cast |
| cyi | Clustify Input File |
| cyp | FCB Cypher Document |
| czd | CAD Zone Drawing |
| d2d | 3D Fassade Plus CAD Document |
| dae | Collada Digital Asset Exchange |
| dap | Microsoft Access Data Access Page |
| dc | DesignCAD Document |
| dc1 | DevCad Document |
| dc2 | DevCad CAM Pro Document |
| dc2 | DesignCAD 2D Document |
| dc3 | DesignCAD 3D Document |
| dc5 | DynaCAD v5 Document |
| dc6 | DynaCAD v6 Document |
| dca | IBM DisplayWrite Document |
| dch | DipTrace Schematic Document |
| dcw | DynaCAD v4 Document |
| dcz | DynaCAD Document |
| ddf | Alpha Journal Pro Document |
| ddf | My Personal Diary Document |