| .C4D | MAXON Computer | Pliki z obrazami 3D | Cinema 4D Model File | Adobe After Effects | Adobe Systems Incorporated |
| .CACHE | Various Developers | Nietypowe Pliki | Cache File | Adobe Photoshop | Adobe Systems Incorporated |
| .CAL | Newera Software Technology, Inc. | Pliki z grafiką rasterową | CALS Raster File | Adobe Photoshop | Adobe Systems Incorporated |
| .CALS | Newera Software Technology, Inc. | Pliki z grafiką rasterową | CALS Raster File | Adobe Photoshop | Adobe Systems Incorporated |
| .CATPRODUCT | Dassault Systèmes | Pliki CAD | CATIA V5 Assembly File | Adobe Acrobat DC | Adobe Systems Incorporated |
| .CCT | Adobe Systems Incorporated | Pliki z danymi | Director Protected Cast Resource | Adobe Director | Adobe Systems Incorporated |
| .CDR | Corel | Pliki z grafiką wektorową | CorelDRAW Vector Image File | Adobe Illustrator CC | Adobe Systems Incorporated |
| .CEF | Richard Stott | Pliki z danymi | Class Action Gradebook Elementary File | Adobe Illustrator CC | Adobe Systems Incorporated |
| .CEL | Affymetrix | Pliki z danymi | Affymetrix Probe Results File | Adobe Audition | Adobe Systems Incorporated |
| .CER | Microsoft Corporation | Plik Web | Internet Security Certificate | Adobe Acrobat DC | Adobe Systems Incorporated |
| .CFA | Frontline | Pliki z danymi | ComProbe Analyzer Capture File | Adobe Premiere Pro CC | Adobe Systems Incorporated |
| .CFC | Adobe Systems Incorporated | Pliki wydawcy | ColdFusion Component File | Adobe Dreamweaver | Adobe Systems Incorporated |
| .CFG | Unknown Developer | Pliki wydawcy | Configuration File | Brackets | Adobe Systems Incorporated |
| .CFM | Adobe Systems Incorporated | Plik Web | ColdFusion Markup File | Adobe Dreamweaver | Adobe Systems Incorporated |
| .CGM | Unknown Developer | Pliki z grafiką wektorową | Computer Graphics Metafile | Adobe Illustrator CC | Adobe Systems Incorporated |
| .CGR | Dassault Systèmes | Pliki CAD | CATIA Graphical Representation File | Adobe Acrobat DC | Adobe Systems Incorporated |
| .CHA | Snak Software | Plik Web | IRC Chat Configuration File | Adobe Photoshop CC | Adobe Systems Incorporated |
| .CIN | Kodak | Pliki z grafiką rasterową | Kodak Cineon Bitmap File | Adobe SpeedGrade | Adobe Systems Incorporated |
| .CLR | Adobe Systems Incorporated | Nietypowe Pliki | Animate Color Set | Adobe Animate CC 2017 | Adobe Systems Incorporated |
| .CLX | IBM | Pliki z danymi | Rational XDE | Adobe Illustrator CC | Adobe Systems Incorporated |
| .CMX | Corel | Pliki z grafiką wektorową | Corel Metafile Exchange Image File | Adobe Illustrator CC | Adobe Systems Incorporated |
| .COLLECTION | Adobe Systems Incorporated | Pliki z danymi | Adobe Bridge Collection File | Adobe Bridge CC | Adobe Systems Incorporated |
| .CONFIG | Unknown Developer | Pliki wydawcy | Configuration File | Brackets | Adobe Systems Incorporated |
| .CP | Apple | Pliki wydawcy | Xcode C++ Source File | Adobe Captivate | Adobe Systems Incorporated |
| .CPD | Adobe Systems Incorporated | Pliki z danymi | RoboHelp Cache Project Database | Adobe RoboHelp | Adobe Systems Incorporated |
| .CPI | Sony | Pliki wideo | AVCHD Video Clip Information | Adobe Premiere Pro CC | Adobe Systems Incorporated |
| .CPR | Steinberg | Pliki audio | Cubase Project | Adobe Captivate | Adobe Systems Incorporated |
| .CPS | Interscape | Pliki gier | The Powder Toy Save File | Adobe Captivate | Adobe Systems Incorporated |
| .CR2 | Canon Inc. | Pliki z aparatu fotograficznego | Canon Digital Camera Raw Image File | Adobe Photoshop Elements | Adobe Systems Incorporated |
| .CRW | Canon Inc. | Pliki z aparatu fotograficznego | Canon Raw CIFF Image File | Adobe Photoshop Elements | Adobe Systems Incorporated |
| .CS | Microsoft Corporation | Pliki wydawcy | C# Source Code File | Adobe Dreamweaver | Adobe Systems Incorporated |
| .CSF | Intergraph Corporation | Pliki GIS | GeoMedia Coordinate System File | Adobe Illustrator CC | Adobe Systems Incorporated |
| .CSH | Adobe Systems Incorporated | Nietypowe Pliki | Photoshop Custom Shapes File | Adobe Photoshop Elements | Adobe Systems Incorporated |
| .CSN | Adobe Systems Incorporated | Pliki wydawcy | Adobe Code Snippet Document | Adobe Dreamweaver | Adobe Systems Incorporated |
| .CST | Smith Micro Software | Pliki z szatami graficznymi | Manga Studio Story File | Adobe Director | Adobe Systems Incorporated |
| .CT | Unknown Developer | Pliki gier | Cheat Engine Cheat Table | Adobe Photoshop | Adobe Systems Incorporated |
| .CTP | Cake Software Foundation | Pliki wydawcy | CakePHP Template | Adobe Dreamweaver | Adobe Systems Incorporated |
| .CXT | Omron Corporation | Pliki wydawcy | CX-Programmer Project Text File | Adobe Director | Adobe Systems Incorporated |
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