| .ckb |
Cricket Audio Bank File |
| .cnd |
Melco Condensed Embroidery File |
| .car |
Car Explorer Data File |
| .crtr |
MultiAd Creator Pro Document |
| .ctx |
Visual Basic Control Binary File |
| .cwb |
Cakewalk Bundle |
| .cxf |
Picasa Collage File |
| .cxd |
SimplePCI Data Document |
| .czd |
CAD Zone Drawing |
| .czi |
Carl Zeiss Image Data File |
| .cnm |
NoteMap Outline File |
| .cm10 |
CaseMap 10 Case File |
| .cdf-ms |
ClickOnce Compiled Manifest File |
| .cgrp |
Pro Tools Clip Group File |
| .clarify |
Clarify Document |
| .cws |
ChordWizard Song |
| .cm5 |
Clone Manager File |
| .comiclife |
Comic Life Document |
| .ciso |
Compact ISO File |
| .cram |
Compressed Alignment File |
| .cosessiondb |
Capture One Session File |
| .cfx |
Flow-Cal Data File |
| .cell |
Thinkfree Office NEO Cell Workbook |
| .cid |
Navigator Chart Image Description File |