| Extension | Information |
| C | ADS Source Code (Autodesk, Inc.) |
| C | C/C++ Program File |
| C | Check Point Site Configuration for Secure Remote |
| C | Desktop Color Separation Specification Cyan Layer |
| C | UNIX Compact File Achive |
| C | Origin C Program File (OriginLab) |
| C V | Cvip File |
| C!_ | Audio Utility Midimach Compressed File |
| C#= | C# (Microsoft) |
| C++ | C++ Source Code |
| C-- | Sphinx C-- Source |
| C00 | Ventura Print File |
| C00 | WinAce Compressed File Split Portion of Compressed File (e-merge GmbH) |
| C01 | WinAce Compressed File Split Portion of Compressed File (e-merge GmbH) |
| C01 | Genesis 2000 (Genesis 2000, Inc.) |
| C02 | WinAce Compressed File Split Portion of Compressed File (e-merge GmbH) |
| C02 | (C02-C38) Driveimage Ace File |
| C03 | WinAce Compressed File Split Portion of Compressed File (e-merge GmbH) |
| C04 | WinAce Compressed File Split Portion of Compressed File (e-merge GmbH) |
| C05 | WinAce Compressed File Split Portion of Compressed File (e-merge GmbH) |
| C06 | WinAce Compressed File Split Portion of Compressed File (e-merge GmbH) |
| C07 | WinAce Compressed File Split Portion of Compressed File (e-merge GmbH) |
| C08 | Lord Of Destruction Game File |
| C08 | WinAce Compressed File Split Portion of Compressed File (e-merge GmbH) |
| C09 | WinAce Compressed File Split Portion of Compressed File (e-merge GmbH) |
| C1 | Povwin Pov-ray for Windows v3.1 Scenes Advanced Newltpot File |
| C10 | WinAce Compressed File Split Portion of Compressed File (e-merge GmbH) |
| C13 | Charlie Packer |
| C2 | Povwin Pov-ray for Windows v3.1 Scenes Advanced Newltpot File |
| C2D | WinOnCD CD Image (Sonic Solutions) |
| C2E | NJStar Chinese Word Processor Dictionary File Index (NJStar Software Corp.) |
| C2I | Driver File |
| C2I | Tt File |
| C2L | Cequadrat WinonCD File |
| C2X | WinonCD File |
| C3 | Pov-ray for Windows v3.1 Scenes Advanced Newltpot File (Persistence of Vision Raytracer Pty Ltd.) |
| C39 | (C39-C56) Quicken Ace File |
| C3D | Chem3D Chemical File |
| C3D | Cult3D Designer Intermediate File |
| C3D | Micrografx |
| C3D | Coordinate 3D |
| C3E | Cype |
| C3T | Chem3D Chemical Template File |
| C4 | Edmics |
| C4 | Joint Engineering Data Management (JEDMICS) DoD Engineering Data Format |
| C4D | Cinema 4D 3D Model (MAXON Computer GmbH) |
| C4D | Clonk Object Definition (RedWolf Design GmbH) |
| C4F | Clonk Round File (RedWolf Design GmbH) |
| C4G | Clonk System File (RedWolf Design GmbH) |
| C4P | Clonk Player File (RedWolf Design GmbH) |
| C4S | Clonk Scenario (RedWolf Design GmbH) |
| C4V | Clonk Video (RedWolf Design GmbH) |
| C6 | Ashlar-Vellum |
| C64 | Commodore 64 Game ROM |
| C86 | Computer Innovation C86 C Program |
| CA | FlexPlus Data File (DATAIR Employee Benefit Systems, Inc.) |
| CA | Telnet Server Initial Cache Data File |
| CA | CLAN Conversion Analysis (Child Language Data Exchange System) |
| CA0 | Installer Packed and Split File (Borland Software Corporation) |
| CA1 | Delphi Install Disk11 File |
| CA1 | OzWin CompuServe E-mail/Forum Access Catalog File |
| CA1 | STABCAL (stability calculation for aqueous systems) File |
| CA2 | Delphi Install Disk12 File |
| CA2 | STABCAL (stability calculation for aqueous systems) File |
| CA3 | Delphi Install Disk9 File |
| CA4 | Delphi Install Disk10 File |
| CA4 | Electronics Workbench Circuit |
| CA4 | STABCAL (stability calculation for aqueous systems) File |
| CA5 | Delphi Install Disk11 File |
| CA7 | Beta 44 Job File |
| CA7 | STABCAL (stability calculation for aqueous systems) File |
| CAB | Cabinet File (Microsoft) |
| CAB | Install Shield v5.x or 6.x Compressed File (InstallShield Software Corporation) |
| CAC | dBASE IV Executable File |
| CAC | Infoview (Microsoft) |
| CAC | Collage Alarm Clock Alarm File (Collage Alarm Clock) |
| CACHE | Snacc-1.3 VDA File |
| CAD | Softdesk Drafix CAD File |
| CAD | QuickCAD CAD Drawing (Autodesk, Inc.) |
| CAD | Inago Rage Compact Arena Definition (Dejobaan Games) |
| CAF | Southern Company Terrestrial Data Acq |
| CAF | Class Action Gradebook Secondary/College Edition Data File (CalEd Software) |
| CAG | Clip Gallery Catalog File (Microsoft) |
| CAG | CADfix ASCII Geometry File (ITI TranscenData) |
| CAI | SeeYou Flight Data (Naviter) |
| CAJ | CAJViewer |
| CAL | Cakewalk Application Language Script (Cakewalk) |
| CAL | Calendar File |
| CAL | CALS Raster |
| CAL | CyberAudioLibrary Link |
| CAL | DOS Calendar Creator File |
| CAL | HTML Calendar Maker Pro |
| CAL | Radiance Function File Format |
| CAL | Schedule Data (Microsoft) |
| CAL | SuperCalc Worksheet |
| CAL | PhotoSmart 850 Digital Camera Firmware Update (Hewlett-Packard Development Company, L.P.) |
| CAL | Creatacard Calendar Project (Broderbund) |
| CAL | QV Map Geographic Coordinates (Touratech) |
| CALS | CALS Raster |
| CAM | Calibrated Camera File Photomodeller |
| CAM | Camtasia Project/Producer Files |
| CAM | Casio QV Digital Camera Image (Casio) |
| CAM | Minolta CAM File |
| CAM | NASCAR Racing 2002 Replay Camera Settings (Sierra) |
| CAM | HouseCall AUTOEXEC.BAT Backup (Trend Micro Inc.) |
| CAM | Mill Data File (GraphiTech Ltd.) |
| CAMS | Driver (Atari) |
| CAN | Canon Navigator Fax |
| CAP | Agilent LAN Analyzer Capture File |
| CAP | Compressed Music File |
| CAP | Fluke Protocol Inspector Capture File |
| CAP | NetMon Capture File (Microsoft) |
| CAP | Sniffer Capture File (Network Associates Technology, Inc.) |
| CAP | ProComm/Telix session Capture File |
| CAP | Shomiti Surveyor Capture File |
| CAP | Sun Snoop Capture File |
| CAP | Telix Session Capture |
| CAP | TTC FireBerd 500 PC Capture File |
| CAP | Ventura Caption |
| CAP | WWG Domino Capture File |
| CAP | WWG LinkView PRO Capture File |
| CAP | Generic Network Capture Document |
| CAP | Code Architect Project File (Embedded Systems Academy) |
| CAPS | Visimetrics Digital CCTV Recording |
| CAR | Creatacard Quarter-Fold Card Project (Broderbund) |
| CAR | AtHome Assistant |
| CAR | Carrara Environment |
| CAR | Insight II Cartesian Coordinate File (Accelrys Software Inc.) |
| CAR | NASCAR Racing 2002 Car Description File (Sierra) |
| CAR | NeoBook Cartoon |
| CAR | Viper Racing Car Description File |
| CAR | PSA Cards Address Book (PSA Software) |
| CAR | CardMaker Ver. 1.0-2.0 Card File (Avery) |
| CAR | CAR Archive Compressed Archive (MylesHi! Software) |
| CAR | Railroad Tycoon 3 Car Properties (PopTop Software Inc.) |
| CAR | Carnivores / Ice Age Resource File (Action Forms, Ltd.) |
| CAR | Design-Your-CD Data File (Avery) |
| CAR | Cellsprings/Web or DT Rule File (J.M.G. Elliott) |
| CAR | SeeYou Airspace (Naviter) |
| CARD | Funkiball Adventure Auto-Saved Game File (RealNetworks Inc.) |
| CAS | Cascade DTP Ver. 3 Layout File (Price Media) |
| CAS | Casio Program |
| CAS | Comma-delimited ASCII File |
| CAS | i2's Case Notebook Timeline Analysis |
| CAS | Quest Compiled Adventure Game (Axe Software) |
| CAS | Atari Cassette Image File (Atari) |
| CAS | Videoton TVC Computer Tape File |
| CAS | FLUENT Case (Fluent Incorporated) |
| CAS4 | Cascade DTP Ver. 4 Layout File (Price Media) |
| CASE | EnSight Results File (Computational Engineering International (CEI)) |
| CAT | Cognos Impromptu Database Report |
| CAT | dBASE Catalog |
| CAT | OzWin CompuServe E-mail/Forum Access Catalog File |
| CAT | PhotoStudio (ArcSoft, Inc.) |
| CAT | Quicken IntelliCharge Categorization File |
| CAT | Rational Rose Logical Package (IBM) |
| CAT | Security Catalog (Microsoft) |
| CAT | Todd Osborne Directory Catalog |
| CAT | Casio Calculator Program (Casio) |
| CAT | TablEdit Chord Catalog |
| CAT | Advanced Disk Catalog Disk Catalog (Elcomsoft) |
| CAT | Catz Cat Description File (http://petz.ubi.com/) |
| CAT | TAPCIS Forum Library Catalog |
| CATALOG | CATIA Catalog (Dassault Systmes) |
| CATANALYSIS | CATIA (Dassault Systmes) |
| CATDRAWING | CATIA Drawing (Dassault Systmes) |
| CATFCT | CATIA (Dassault Systmes) |
| CATMATERIAL | CATIA Material Specification (Dassault Systmes) |
| CATPART | CATIA Part Description (Dassault Systmes) |
| CATPROCESS | CATIA Process Description (Dassault Systmes) |
| CATPRODUCT | CATIA Product Description (Dassault Systmes) |
| CATPRODUCT | CATIA (Dassault Systmes) |
| CATSHAPE | CATIA Shape (Dassault Systmes) |
| CATSWL | CATIA (Dassault Systmes) |
| CATSYSTEM | CATIA (Dassault Systmes) |
| CAZ | Computer Associates Archive |
| CA_ | Cakepro Compressed Audio File |
| CB | Brief Macro Source Code |
| CB | Clean Boot File (Microsoft) |
| CB | Crystal Button File |
| CB | COMBAS Source Code (Living Byte Software GmbH) |
| CB | Gigascape Virtual Town Project (Third Dimension Limited) |
| CB3 | CliBench Mk III SMP 0.7.10 |
| CBC | CubiCalc Fuzzy Logic System File |
| CBD | System DLL Catroot File |
| CBF | Calendar Builder Saved Calendar (RKS Software) |
| CBF | Infinity Game Engine Archive of Resources (BioWare Corp.) |
| CBF | CoffeeCup Button Factory Button (CoffeeCup Software, Inc.) |
| CBH | ChessBase Chess Database File |
| CBI | IBM Mainframe Column Binary Formatted File |
| CBK | CardScan Backup File (Corex Technologies) |
| CBK | National Construction Estimator 32 Costbook |
| CBK | System DLL Catroot File |
| CBL | COBOL Program |
| CBL | Contextual Browsing Language Viewer |
| CBL | RM/COBOL Development System Source File (Liant) |
| CBL | CD Box Labeler Pro (Green Point Software UK Ltd.) |
| CBM | Fuzzy Bitmap |
| CBM | XLib Compiled Bitmap |
| CBN | CBN Selector Smart Image (CBN Systems) |
| CBN | PaperMaster Cabinet (j2 Global Communications, Inc.) |
| CBO | COMBAS Object File / Compiled Program (Living Byte Software GmbH) |
| CBP | CentraBuilder (CentraLearning International) |
| CBP | CD Box Labeler Pro (Green Point Software UK Ltd.) |
| CBR | CDisplay RAR Archived Comic Book File |
| CBS | Borland Computer Based Training (Borland Software Corporation) |
| CBS | Cardbox Macro Script |
| CBS | MasterWord Button Bar Configuration |
| CBS | Computer Based Training (Microsoft) |
| CBS | Calendar Builder Style Sheet (RKS Software) |
| CBT | Computer Based Training |
| CBV | ChessBase Archive File |
| CBW | Cardbox Workspace |
| CBX | Rational XDE (IBM) |
| CBZ | CDisplay ZIP Archived Comic Book File |
| CC | ADS Source Code (Autodesk, Inc.) |
| CC | C++ Program File |
| CC | CC Language Source Code |
| CC | dB2K Custom Class File |
| CC | Picture Window's Color Curve File |
| CC | Visual dBASE Custom Class File |
| CC | Trojan Spymaster.A Text File |
| CC | KODAK Color Control Profile (KODAK) |
| CC1 | Briggs Softworks Calendar Commander |
| CC1 | Chem3D Cartesian Coordinates 1 |
| CC2 | Chem3D Cartesian Coordinates 2 |
| CC2 | ClubControl 2 |
| CC2 | Calendar Commander Calendar File (Briggs Softworks) |
| CC3 | CUEcards Professional Database (Marcus Humann) |
| CC5 | Calendar Creator 5.x 6.x File |
| CCA | CC:Mail Archive File (IBM) |
| CCA | Multimedia Fusion File |
| CCA | Common Component Architecture (CCA) Component (Dept. of Energy Laboratories) |
| CCAD | ClarisCAD data |
| CCB | Visual Basic Animated Button Configuration |
| CCC | Curtain Call Native Bitmap Graphic |
| CCC | Internet Chat (Comic Chat) Conversation/Chatroom Log (Microsoft) |
| CCC | WordPerfect Office Calendar File (Corel Corporation) |
| CCD | CloneCD Control File (SlySoft Inc.) |
| CCD | Vector CAD Program File |
| CCD | IsoBuster Data Recovery File (Smart Projects) |
| CCDOC | Rational CCDoctor Output (IBM) |
| CCE | Calendar Creator 2 Event File |
| CCF | AudioReQuest Control File |
| CCF | Card Studio Card File Template (Hallmark) |
| CCF | OS/2 Multimedia Viewer Configuration File |
| CCF | Remote Control File |
| CCF | Symphony Communications Configuration File |
| CCF | Cannondale Motorcycle ECM System Engine Calibration File (Cannondale Corp.) |
| CCF | CommView Capture File (TamoSoft, Inc.) |
| CCF | GPS Pathfinder Office Configuration File (Trinble Navigation Limited) |
| CCF | Cumulus Database (Canto) |
| CCH | Corel Chart |
| CCH | Fabasoft Components |
| CCH | Forgotten Realms Unlimited Adventures (FRUA) Character Reference File |
| CCH | Photomodeler Photochip Thumbnail File (OES Systems) |
| CCH | PhotoModeler |
| CCI | CCITT Group 3 and Group 4 Encoding |
| CCITT | CCITT Group 3 and Group 4 Encoding |
| CCJ | Crossword Compiler Compiled Crossword Applet (Antony Lewis) |
| CCK | Corel Clipart Format (Corel) |
| CCL | Intalk Communication Command Language |
| CCM | CC:Mail Mailbox (IBM) |
| CCN | IMSI Multimedia Fusion Express File |
| CCN | Vitalize! Game File |
| CCN | Calendar Constructer Calendar Data (Aspire Software) |
| CCO | CyberChat Data File |
| CCO | MicroSim PCBoard Autorouter Session Output |
| CCO | XBTX BTX Graphics File |
| CCP | C Converter Profiles |
| CCP | CalComp Color Palette File |
| CCP | CloneCD (SlySoft Inc.) |
| CCP | CaptureCAM-PRO Screen Recording (Click-N-Learn PTY LTD) |
| CCP | Two Brothers Software Encrypted File Information (Two Brothers Software) |
| CCPR | CaptureCAM-PRO (Click-N-Learn PTY LTD) |
| CCR | Internet Chat Room Shortcut (Microsoft) |
| CCRF | Calcomp Raster Bitmap |
| CCS | CCS-lib File |
| CCS | CONKY CeZaR Stribas International |
| CCT | DesignWorks Schematic File (Capilano Computing) |
| CCT | Macromedia Director Shockwave Cast |
| CCT | MicroSim PCBoard Design Information and Rules For Autorouting |
| CCT | SIL Hebrew Font System Transliteration Table |
| CCT | LogicWorks Schematic File (Capilano Computing) |
| CCT | Railroad Tycoon 3 Car Type Description (PopTop Software Inc.) |
| CCV | Crystal Vision Report (CTMS) |
| CCX | Corel Compressed Exchange File |
| CCX | CorelDraw File |
| CCX | Total Annihilation: Counter-Strike |
| CCX | Multimedia Fusion Extension (Clickteam) |
| CC_ | Audio Utility Midimach Compressed File |
| CD | cdTree Content List |
| CD | CD-i OptImage CD Image |
| CD1 | Cafeteria Document System Data File (DATAIR Employee Benefit Systems, Inc.) |
| CD2 | Cafeteria Document System Custom Text File (DATAIR Employee Benefit Systems, Inc.) |
| CDA | CD Audio Track Shortcut |
| CDAT | Internet Security and Acceleration (ISA) Server Cache File (Microsoft) |
| CDB | CardScan Database (Corex Technologies) |
| CDB | Clipboard File |
| CDB | Nokia 9210/9290 Phone Contact Database (Nokia) |
| CDB | One Page from a ROM With a View Project File |
| CDB | PowerDesigner Conceptual Model Backup File |
| CDB | SymbianOS Contact Database File |
| CDB | Turbo C Database (Borland Software Corporation) |
| CDB | The Cleaner Trojan Database (Moosoft Development LLC.) |
| CDB | Pocket Access Database (Microsoft) |
| CDB | SeeYou Waypoint (Naviter) |
| CDBK | SPSS Database File |
| CDC | Chromeleon Driver Configuration Plug-in |
| CDC | Nero CD Cover File (Nero AG) |
| CDC | Canvastic Documnet/Drawing (Canvastic) |
| CDC | CLAN Debug File (Child Language Data Exchange System) |
| CDD | Chromeleon Device Driver |
| CDD | Claris Draw v 1.2 Document |
| CDD | Concept Draw Drawing/Diagram (Computer Systems Odessa, Corp.) |
| CDD | CD-Architect Driver File (Sonic Foundry) |
| CDD | CADAM Drawing (Dassault Systemes) |
| CDD | Balder Multiboot Configuration File (Hans Christian Ihlen) |
| CDD | Cadifra Diagram (Cadifra Inc.) |
| CDDA | AIFF Audio |
| CDE | CADKEY Dynamic Extension (CADKEY) |
| CDE | Honeywell Hybrid Control Designer |
| CDF | ASCII Format Describing VRML Worlds |
| CDF | Channel Definition Format (Microsoft Corporation) |
| CDF | Comma Delimited Format |
| CDF | Cyberspace Description Format |
| CDF | InstallShield Components Definition File (InstallShield Software Corporation) |
| CDF | MicroSim PCBoard Component Description File For Bill Of Materials |
| CDF | Unidata NetCDF Graphic File (University Corporation for Atmospheric Research) |
| CDF | ANDI/netCDF Mass Spectrometry Data Interchange format |
| CDG | DART Karaoke Studio CD+G File |
| CDI | Disc Juggler CD Image File |
| CDI | Phillips Compact Disk Interactive Format |
| CDI | CD Anywhere Virtual CD (V Communications, Inc.) |
| CDJ | Disc Juggler File |
| CDK | Calamus Document (invers Software) |
| CDK | CD Katalog (KRISoftware) |
| CDKEY | Protocol Used in Communicating from MediaRemote Server to PC MediaRemote Plug-in |
| CDL | CADKEY Advanced Design Language (CADL) (CADKEY) |
| CDL | CaseWare Working Papers Document Link |
| CDL | SignLab Vector Graphic |
| CDM | Compressed Music Format |
| CDM | Novell NetWare Disk Drivers NPA |
| CDM | PowerDesigner Conceptual Model File |
| CDM | Visual dBASE Custom Data Module |
| CDO | Cdo Navigator |
| CDO | CADAM Overlay (Dassault Systemes) |
| CDP | CD/Spectrum Pro |
| CDP | Ca Visual Objects Platform for Developer (CAVO) (CA) |
| CDPRJ | CD Menu Creator Project File (Drackon Tech) |
| CDQ | CD Indexer |
| CDR | Corel Vector Graphic Drawing (Corel) |
| CDR | Raw Audio-CD Data |
| CDR | Sound File |
| CDR | Elite Plus Commander Saved Game |
| CDR | GameJack Virtual CD or DVD Image (S.A.D. GmbH.) |
| CDR | Final Cut Pro CD/DVD Image File (Apple Computer, Inc.) |
| CDS | ChemDraw Stationery Document |
| CDS | Delphi TClientDataset Data (Borland Software Corporation) |
| CDS | United States Postal Service Computerized Delivery Sequence |
| CDSG | DrawMusic Chord Song (Conrad Albrecht) |
| CDT | CorelDraw Template (Corel) |
| CDT | ProWORX Nxt Temporary Long Comment Data (Schneider Electric) |
| CDT | STABCAL (stability calculation for aqueous systems) File |
| CDU | CDU Paint |
| CDV | CatDV Media Catalog (Square Box Systems Ltd.) |
| CDW | CADKEY Organized Dialog File (CADKEY) |
| CDW | CeledyDraw Image |
| CDX | Active Server Document |
| CDX | ChemDraw Chemical Structure |
| CDX | Compound Index |
| CDX | Corel Draw Compressed Drawing |
| CDX | Microstation Cell Library Index |
| CDX | Visual Foxpro Index (Microsoft) |
| CDX | NovaBACKUP Backup Database Index (NovaStor Corporation) |
| CDX | Alpha Five Table Index (Alpha Software, Inc.) |
| CDXL | Old Amiga Movie Format |
| CDXML | ChemDraw XML ChemDraw Format |
| CDZ | ROM With a View Project File |
| CE | CA Clipper Workbench Application |
| CE | Computer Eyes, Digital Vision |
| CE | FarSide Computer Calendar File |
| CE1 | Computer Eyes Raw Low Resolution Image |
| CE2 | Computer Eyes Raw Medium Resolution Image |
| CE3 | Calendar Creator 3.x 4.x Event List |
| CEF | CA Clipper Workbench Application |
| CEF | CruzerLock Encrypted File (SanDisk Corporation) |
| CEF | Class Action Gradebook Elementary Edition Data File (CalEd Software) |
| CEF | CenturionMail Encrypted File (CenturionSoft) |
| CEF | Spaix PumpSelector Catalog Exchange Format (VSX - VOGEL SOFTWARE GMBH) |
| CEG | Continuous Edge Graphic Bitmap (Edsun) |
| CEG | Tempra Show Bitmap Graphic |
| CEI | CRiSP Harvest File |
| CEL | Animator Graphic (Autodesk, Inc.) |
| CEL | CIMFast Event Language File |
| CEL | Celestia 3D Rendering Script |
| CEL | KiSS Paper Doll File |
| CEL | Audition Loop File (Adobe) |
| CEL | Lumena CEL Bitmap (Time Arts Software) |
| CEL | Microstation Cell Library |
| CELX | Celestia 3D Rendering Script |
| CEM | Computer Graphics Metafile |
| CEM | Empire Earth Game File |
| CEN | Master Tracker Financial Analysis |
| CEO | Extension associated with Winevar Worm |
| CER | Internet Security Certificate File |
| CER | Lahey Fortran Compilation Error Messages |
| CER | Sierra Print Artist Certificate |
| CER | Creatacard Certificate Project (Broderbund) |
| CES | Sheffield Dictionary File |
| CEV | LOUT Character Encoding File |
| CEV | Software License Tracking Tool |
| CEX | INMOS Transputer Development System Occam User Program |
| CEX | The Currency Exchanger Rate File |
| CEX | ThumbsPlus File |
| CEX | CLAN Output File (Child Language Data Exchange System) |
| CF | Imake Configuration File |
| CF | Sendmail Configuration File |
| CF1 | Common File Format 1 |
| CF2 | Common File Format 2 |
| CF4 | Catfish File Manager Support File |
| CFB | Comptons Multimedia File |
| CFB | Inmos Binary Configuration File |
| CFC | Cold Fusion File |
| CFD | CryptoForge Document (Ranquel Technologies) |
| CFDG | Context Free Design Grammar |
| CFE | CryptoForge Encrypted File (Ranquel Technologies) |
| CFF | Capabilities File for FOUNDATION Fieldbus H1 |
| CFF | Common File Format |
| CFF | BoomTracker 4.0 |
| CFG | Configuration |
| CFG | Pro/ENGINEER Configuration (PTC) |
| CFG | Proxomitron Configuration File (Scott R. Lemmon (deceased)) |
| CFH | Capabilities File for FOUNDATION Fieldbus HSE |
| CFK | Kardplay 1.62 File |
| CFK | MS Developer Studio Diagram |
| CFL | Corel Flowchart File |
| CFL | Developer Studio Diagram (Microsoft) |
| CFL | Compressed File Library File (Compressed File Container) |
| CFM | Cold Fusion Template File |
| CFM | Corel FontMaster |
| CFM | Visual dBASE Windows Customer Form |
| CFML | Cold Fusion Markup Language |
| CFN | Calamus Font Data (invers Software) |
| CFO | TCU Turbo C Utilities C Form Object |
| CFO | Turbo C (Borland Software Corporation) |
| CFP | Complete Fax Portable Fax File |
| CFR | IBM Configurator Report |
| CFR | NRC Inspection Manual CFR Guidance |
| CFS | Inmos Configuration File |
| CFS | Signal Data (Cambridge Electronic Design Limited) |
| CFT | Animation Studio CFast Graphics File (Disney) |
| CFT | Cumberland Family Tree |
| CFT | Flow Chart; Corel Flow Template |
| CFW | ChemFinder Form |
| CFX | Creative DSP File |
| CFX | Flow-Cal File |
| CG | Norton Crashguard File |
| CG3 | Dungeons & Dragons Character File (Wizards of the Coast, Inc.) |
| CGA | CGA Resolution BMP Bitmap |
| CGA | Color Graphics Adapter Graphics Data |
| CGA | Ventura CGA Screen Characters |
| CGB | Gameboy Color |
| CGF | Asm Objasm |
| CGF | ProWORX Nxt CODEGEN Batch File (Schneider Electric) |
| CGF | Family Tree Creator Deluxe (Broderbund) |
| CGF | Egrid32 Grid Format File (Sweetheartgames.com) |
| CGI | Common Gateway Interface Script |
| CGL | CodeGuard Error Log |
| CGM | Computer Graphics Metafile [Old Style] |
| CGM | Computer Graphics Metafile [New Style] |
| CGO | Railroad Tycoon 3 Car Properties (PopTop Software Inc.) |
| CGP | NetCaptor CaptorGroup (Stilesoft, Inc.) |
| CGR | Quest3D Program Part (Act-3D B.V.) |
| CH | Clipper Header |
| CH | OS/2 Configuration File |
| CH1 | Freelance CHart |
| CH3 | Harvard Graphics Chart (Harvard Graphics) |
| CH4 | Charisma 4.0 Presentation |
| CHA | Character Data |
| CHA | mIRC Chat File |
| CHA | PageMaker Kerning Data (Adobe) |
| CHA | CLAN Frequency Sample File (Child Language Data Exchange System) |
| CHANGES | Squeak Change File |
| CHAT | PIRCH98 Chat File |
| CHB | Oledb Checkbook File |
| CHD | Ares FontChameleon Font Descriptor |
| CHD | ChartFX File |
| CHD | MAME Compressed Hard Disk File (MAME Team) |
| CHF | pcAnywhere Remote Control File |
| CHG | Quicken On-line Data File (Intuit) |
| CHH | C++ Header |
| CHI | ChiWriter Document |
| CHI | Help File Index (Microsoft) |
| CHJ | Help Composer Project |
| CHK | CHKDSK/SCANDISK Output |
| CHK | Sophos Intercheck File |
| CHK | Starcraft Campaign Map |
| CHK | WordPerfect Temporary File (Corel Corporation) |
| CHK | SSConvert Multilanguage Video Subtitle Data (Screen Subtitling Systems Ltd.) |
| CHK | 3D Movie Maker Interface Data File (Microsoft) |
| CHK | EpiData Check File (EpiData Association) |
| CHL | Chromeleon Channel Raw Data |
| CHL | Configuration History Log |
| CHL | Internet Explorer Channel Information (Microsoft) |
| CHL | RealPlayer Live Channel |
| CHM | Ares Font Chameleon Source Font; font outline |
| CHM | ChemDraw Chemical Structure (CambridgeSoft Corporation) |
| CHM | HTML Help Compiled Help File (Microsoft) |
| CHN | Ethnograph Data File |
| CHO | Animation:Master Choreography (Hash) |
| CHO | Ares Font Chameleon Output Font |
| CHO | Chord Pro Song Format (Mussoft) |
| CHOPRO | Chord Pro Song Format (Mussoft) |
| CHP | Ventura Publisher Chapter (Corel Corporation) |
| CHP | FLOWer (Pallas Athena) |
| CHP | BizInt Smart Charts for Patents Document (BizInt Solutions) |
| CHP | DVD Chapter File |
| CHP | CodeHealer Project File (SOCK Software, LLC) |
| CHQ | Help Combined Full-text Search File (Microsoft) |
| CHR | Borland Language Stroke Font File (Borland Software Corporation) |
| CHR | Character or Font File |
| CHR | Infinity Game Engine Exported Character Info (BioWare Corp.) |
| CHR | Wormhole 2.0/ Liero Graphics Editor Liero Graphics Mod |
| CHS | ATI Radeon Video Driver |
| CHS | Corel WP Chart Style |
| CHS | ChessRally Saved Game/E-mail Attached Game (Ingenuware, Ltd.) |
| CHT | ChartFX Template File |
| CHT | Chartist from Novagraph |
| CHT | ChartViewer dBASE Interface File |
| CHT | Cheat Machine Data File |
| CHT | Sierra Generations Family Tree Chart (Sierra Entertainment, Inc.) |
| CHT | Harvard Graphics Vector File (Harvard Graphics) |
| CHT | ICQ Saved Chat Session (ICQ Inc.) |
| CHT | Novagraph Chartist File |
| CHT | ZSNES Cheat Code (ZSNES Team) |
| CHT | BizInt Smart Charts for Drug Pipelines Document (BizInt Solutions) |
| CHU | Infinity Game Engine GUI Elements File (BioWare Corp.) |
| CHW | HTML Help General Index Funtionally comparable to .GID. |
| CHZ | ChArc Compressed File Archive |
| CI | CitectSCADA File |
| CI2 | Calin Lawyer's Interest Calculator Ver 2 Data File (Lawtech (Aust) Pty Ltd.) |
| CI3 | Calin Lawyer's Interest Calculator Data File (Lawtech (Aust) Pty Ltd.) |
| CIA | Sheffield Dictionary File |
| CIF | CalTech Intermediate Graphic |
| CIF | Chip Layout Information |
| CIF | Colombo Ipermedia File |
| CIF | Crystallographic Information File |
| CIF | Easy CD Creator Image (Sonic Solutions) |
| CIF | Ariba Buyer Catalog Information Format (Ariba Inc.) |
| CIF | pcAnywhere Caller File |
| CIF | Ventura Chapter Information |
| CIF | Ventura Converted Image File |
| CIF | Creator Document File (MultiAd, Inc.) |
| CIG | Fastback Plus Compressed Backup |
| CIK | Corel Graphics Ver. 10 Custom Dual Tone File (Corel) |
| CIK | Norton CleanSweep Installation Log (Symantec) |
| CIL | Clip Gallery Download Package (Microsoft) |
| CIL | Norton CleanSweep Installation Log (Symantec) |
| CIM | CIMEX Cimpack Design Drawing File |
| CIM | CompuApps Drive Backup Image |
| CIM | GE Industrial Systems CIMPLICITY HMI Screen |
| CIM | SimCity 2000 (Electronic Arts, Inc.) |
| CIM | The Ultimate Draw C Text Mode Image File |
| CIN | Cinemania (Microsoft) |
| CIN | Cinetitler Digital Screen Subtitling |
| CIN | Digital Moving Picture Exchange Bitmap (The Society of Motion Picture and Television Engineers) |
| CIN | Cineon Bitmap (Kodak) |
| CIN | OS/2 Change Control File |
| CIN | Photo-Sonics Picture Sequence |
| CIN | Quake II Cinematic Video (id Software) |
| CIN96LM | See .CIN |
| CIN96UPD | See .CIN |
| CIP | Ghost Keylogger File |
| CIP | CryptoBuddy Encrypted File (Research Triangle Software) |
| CIPO | Internet Same as .CPI. |
| CIQ | CableIQ Test Data (Fluke Networks) |
| CIR | PSpice File (OrCAD) |
| CIR | SuperMax E-CAD Save-File Command |
| CIR | real-PCB Netlist (Crocodile Clips Ltd) |
| CIS | CheckInbox File |
| CIS | TAPCIS Parameter/Address Book/Rates File |
| CIT | Intergraph Scanned Image |
| CIT | Norton CleanSweep Installation Log (Symantec) |
| CIT | SeeYou Vector Maps (Naviter) |
| CIV | Empire Earth Custom Civilization Information |
| CIX | TCU Turbo C Utilities Database Index |
| CIX | Rational XDE (IBM) |
| CJB | cleaner XL Job (discreet (an Autodesk Company)) |
| CJP | WinOnCD Project File (Sonic Solutions) |
| CK1 | iD/Apogee Commander Keen 1 Data File |
| CK2 | iD/Apogee Commander Keen 1 Data File |
| CK2 | iD/Apogee Commander Keen 2 Data File |
| CK3 | iD/Apogee Commander Keen 1 Data File |
| CK3 | iD/Apogee Commander Keen 3 Data File |
| CK4 | iD/Apogee Commander Keen 1 Data File |
| CK4 | iD/Apogee Commander Keen 4 Data File |
| CK5 | iD/Apogee Commander Keen 1 Data File |
| CK5 | iD/Apogee Commander Keen 5 Data File |
| CK6 | iD/Apogee Commander Keen 1 Data File |
| CK6 | iD/Apogee Commander Keen 6 Data File |
| CKB | C++ Keyboard Mapping File (Borland Software Corporation) |
| CKD | CADKEY Design File (CADKEY) |
| CKI | Off by One Browser Persistent HTTP Cookies (Off By One Productions, a division of Home Page Software Inc.) |
| CKO | KnockOut 2 Image Mask (Corel) |
| CKP | Ingres Checkpoint File (Computer Associates International, Inc.) |
| CKP | Valise Secure Archive (CertainKey, Inc.) |
| CKT | CADKEY Template File (CADKEY) |
| CKT | Crocodile Clips |
| CKT | CircuitMaker Schematic (Altium Limited) |
| CL | Generic LISP Source Code |
| CL | ArtIcons Pro Cursor Library (Aha-soft) |
| CL3 | Bruker Aspect NMR Data File |
| CL3 | Easy CD Creator Layout File (Sonic Solutions) |
| CL4 | Easy CD Creator Ver 4 Layout File (Sonic Solutions) |
| CL5 | Easy CD Creator Layout File (Project) (Sonic Solutions) |
| CLA | Clarion for DOS Source Code (SoftVelocity) |
| CLA | Java Class File (Sun) |
| CLASS | Java Bytecode (Sun) |
| CLASS | Java Class File (Sun) |
| CLB | cdrLabel Compact Disc Label |
| CLB | Corel Library |
| CLB | ICQ Contact List (ICQ Inc.) |
| CLB | Office XP Developer Code Librarian (Microsoft) |
| CLB | Super NoteTab ClipBook Template |
| CLB | Total Club Manager Single Club Info (Electronic Arts Inc.) |
| CLC | Corel Catalog |
| CLC | Schedule+ 7-Habits Mission Statement (Microsoft) |
| CLD | CA Clipper Debugger Configuration File |
| CLD | Skerryvore Software Simply Calenders |
| CLD | Terragen Cloud Layer File (Planetside Software) |
| CLD | CD-Label Print Label Layout File (Canon, Inc.) |
| CLDLYR | Terragen Cloud Layer File (Planetside Software) |
| CLE | Icon Lock-iT Locked File Indicator (Moon Valley Software, Inc.) |
| CLF | ListPro Database (Ilium Software, Inc.) |
| CLG | Disk Catalog Database |
| CLG | Maxagrid CTM Log File |
| CLI | Client Management System Customer File (HawkSoft, Inc.) |
| CLK | R.A.V.E. Animation File (Corel) |
| CLKX | Clicker Grid Set (Crick Software Ltd.) |
| CLL | Crick Software Clicker File |
| CLL | OzWin CompuServe E-mail/Forum Access Custom Library Search |
| CLM | Micrografx Picture Publisher 7 Macro |
| CLN | Backup Configuration File |
| CLO | Cloe Ray-Tracer |
| CLO | SPSS Chart Look (SPSS, Inc.) |
| CLOE | Cloe Ray-Tracer |
| CLP | Clipper 5 Compiler Script |
| CLP | CLIPS/wxCILPS File |
| CLP | GoDot |
| CLP | PC Paint/Pictor Picture |
| CLP | Quattro Pro Clip Art (Corel) |
| CLP | Windows Clipboard/Picture |
| CLR | 1st Reader Binary Color Screen Image |
| CLR | Boxer/2 Color Scheme |
| CLR | FileMaker Spelling Dictionary |
| CLR | PhotStyler Color Definition |
| CLR | WinEdit Colorization Word List |
| CLR | Flash Color Table File (Macromedia) |
| CLR | WinMX Color Scheme (Frontcode Technologies) |
| CLS | ArcView Geocoding Classification File (ESRI) |
| CLS | C++ Class Definition |
| CLS | JavaScript Class |
| CLS | MS VB-4 Class Module Add-In |
| CLS | MS VisC++/Visual Basic Class Definition |
| CLS | Visual Basic Class Module |
| CLT | VisualBoyAdvance Cheat List (Forgotten and VBA Team) |
| CLU | XNBC V8 Biological Neural Network Simulation Workstation Cluster Names |
| CLU | Broken Sword 2 Dialog File (THQ Inc.) |
| CLU | IBM PCI Cryptographic Coprocessor Code File (IBM) |
| CLU | Phantasmagoria 2 8-bit Playback Pallete File |
| CLU | Clusse Node File (Heikki Hannikainen) |
| CLV | Vbox Current Language File (Aladdin Knowledge Systems) |
| CLV | Clovis for Outlook Schema Settings (Steelhead Systems) |
| CLW | Clarion for Windows Source Code (SoftVelocity) |
| CLW | Visual C++ Class Wizard File (Microsoft) |
| CLX | Macro ToolsWorks Macro |
| CLX | Acrobat (Adobe) |
| CLX | Rational XDE (IBM) |
| CLY | Corel Graphics Ver.10 Custom Layouts File (Corel) |
| CLY | ACT! Layout (Best Software CRM Division) |
| CL_ | C Poet compressed Disk1 File |
| CM | Craftman Data File |
| CM | Unix Puzzle 8-bit Bitmap |
| CM2 | Curious Labs Poser Camera File |
| CM4 | ClipMate Data File |
| CM4 | Championship Manager 4 Saved Game (Sports Interactive Ltd.) |
| CMA | Applix TM1 Database |
| CMA | Filetopia Collection Manager List (Filetopia) |
| CMA | Camomile Library File |
| CMAP | CmapTools Concept Map (IHMC) |
| CMB | Chromeleon Backup Archive |
| CMB | Xtree for Windows Button Bar |
| CMC | PowerFront File |
| CMC | Collectorz.com Comic Collector Collection Data (Collectorz.com) |
| CMD | 1st Reader External Command Menu |
| CMD | Command File for Windows NT (Microsoft) |
| CMD | dBASE II Program File |
| CMD | DOS CP/M Command File |
| CMD | OS/2 |
| CMD | OS/2 REXX Batch File |
| CMDF | CrystalMaker |
| CME | Crazy Machines Level File (Pepper Games) |
| CMF | Corel Metafile |
| CMF | Creative Music File |
| CMF | Connection Manager Fixer File |
| CMF | CopyMate Data File (GraphiTech Ltd.) |
| CMG | Chessmaster Saved Game |
| CMG | cramfs ROM Filesystem Package |
| CMI | CD Mate CD Burning Image File (An Chen Computers Co. Ltd.) |
| CMI | Camomile Interface File |
| CMK | Card Shop Plus File |
| CML | Cheat Machine Library File |
| CML | Chemical Markup Language Document |
| CML | Filetopia Collection Manager List (Filetopia) |
| CML | PADGen Company Info File |
| CML | ProWORX Nxt Comment Data (Schneider Electric) |
| CML | Crazy Machines Saved Laboratory File (Pepper Games) |
| CMM | CEnvi (ScriptEase:Desktop) Batch File |
| CMO | Virtools Behavioral Server Composition |
| CMP | Address Document |
| CMP | Chord Pro Song Format (Mussoft) |
| CMP | CorelDRAW Postscript Printer Header |
| CMP | CraftMan Data |
| CMP | Discorp CMP Image |
| CMP | Generic CADD Component File |
| CMP | Internet Explorer Custom Menu Plug-in (Microsoft) |
| CMP | JPEG Bitmap |
| CMP | Leadview (LEAD) Bitmap |
| CMP | Open Access File |
| CMP | Photofinish Calibration MaP |
| CMP | PKWare Compression Library Compressed Data |
| CMP | Route 66 Address Document |
| CMP | SWAT 3 Compressed Sound File |
| CMP | Technics Keyboard Composer File |
| CMP | Word for DOS User Dictionary (Microsoft) |
| CMP | HotDocs Template Component File (Matthew Bender & Company, a member of the LexisNexis Group) |
| CMP | Freelancer Physical Model Layout (Microsoft) |
| CMQ | Culturemetrics |
| CMR | CribMaster File |
| CMR | MediaPlayer Movie |
| CMR | SeeYou Raster Maps (Naviter) |
| CMRT | CraftMan Data |
| CMS | TrialDirector Compound Media Storage |
| CMT | Chinon ES-1000 Digital Camera |
| CMT | Corel Draw |
| CMT | Culturemetrics |
| CMT | e-Sword Commentary (Rick Meyers) |
| CMTD | Cool Moon To Do To Do List (Cool Moon Software, LLC.) |
| CMU | Carnegie Mellon Univeristy Stereo Raster Image |
| CMU | CMU Window Manager Bitmap |
| CMUWM | Carnegie Mellon University (CMU) Window Manager Bitmap |
| CMV | CorelDRAW 4.0 Movie Animation (Corel Corporation) |
| CMW | COM-Watch |
| CMW | Custom Maintenance Wizard File (Microsoft) |
| CMX | Apple Viewer (Apple Computer, Inc.) |
| CMX | Presentation Exchange Image (Corel) |
| CMX | Patch File |
| CMX | The Sims 3D Body Mesh Data (Electronic Arts (Maxis)) |
| CMX | Rational XDE (IBM) |
| CMXA | Camomile Packed Library File |
| CMY | Corel40 Custom File |
| CMYK | Raw Cyan, Magenta, Yellow, and Black Samples |
| CNB | Pegasus Mail Mail Message in Noticeboard (David Harris) |
| CNC | Click 'n Create File |
| CNC | CNC General Program Data |
| CND | ControlDraw File |
| CND | Embroidery Design File |
| CNF | 1-2-3 Configuration (IBM) |
| CNF | Conference Link |
| CNF | Configuration File Used by Telnet, Windows, and other applications with varying internal formats. |
| CNF | Inor MinIpaq Software File |
| CNF | Windows SpeedDial (Microsoft) |
| CNF | KiSS Paper Doll Set |
| CNM | Windows Application Menu Options and Setup File |
| CNM | WinRoute Electronic Mail File (Kerio Technologies Inc.) |
| CNM | Pegasus Mail New Mail Message (David Harris) |
| CNQ | Compuworks Design Shop File |
| CNR | CRiSP Harvest File |
| CNR | Pegasus Mail Mail Message in Systemwide Folder (David Harris) |
| CNREG | EULANDA Warenwirtschaft (ERP) Configuration Information |
| CNREP | EULANDA ERP System Report Template |
| CNS | Windows2000 Client Connection Manager Export File (Microsoft) |
| CNT | Help File Contents |
| CNT | Rational Rose 98 Contents Tab File (IBM) |
| CNV | Canvas Versions 6, 7, 8, 9 Graphic File (ACD Systems Ltd.) |
| CNV | Word Data Conversion File (Microsoft) |
| CNV | WordPerfect Temporary File (Corel Corporation) |
| CNV | WS_FTP Pro Upload Conversion File Data |
| CNV | DB2 Conversion File |
| CNX | Rational XDE (IBM) |
| CN_ | Regeditx File |
| CO | Cult3D ActiveX Player Application |
| CO$ | MS Compressed COM Decompress with UNPACK.EXE. |
| COA | TrueSpace 3D Object (Caligari Corporation) |
| COA | Medlin Accounting Chart of Accounts With Beginning of Year Balances (Medlin Accounting) |
| COB | TrueSpace Object (Caligari Corporation) |
| COB | COBOL Program File |
| COB | RM/COBOL Runtime System Application File (Liant) |
| COB | TrueSpace2 Object |
| COB | Total Annihilation Unit Script (Cavedog Entertainment) |
| COB | Creatures Compiled Object File (Gameware Development Ltd.) |
| COD | Boxer/2 printer Code Definition File |
| COD | C Compiler Output (Microsoft) |
| COD | Charset Code File |
| COD | Code List |
| COD | Compiler Program Code |
| COD | dBASE Application Generator Template Source File |
| COD | dBASE Template Source File |
| COD | Forecast Plus |
| COD | FORTRAN Compiled Code |
| COD | Multiplan Data File (Microsoft) |
| COD | StatPac Gold Datafile |
| COD | SWAT Input Control File |
| COD | UUPC Code Definition Table |
| COD | Video Text File |
| COD | Agent Charmap (Fort) |
| CODE | Graal and Related Servers Encrypted Cache (Cyberjoueurs) |
| COK | Carmageddon Patch File |
| COL | Autodesk Color Palette (Autodesk, Inc.) |
| COL | Grand Theft Auto III Collision Data (Take-Two Interactive Software, Inc.) |
| COL | Internet Color Wizard Color Scheme |
| COL | Notes Import Column Description File (IBM) |
| COL | Movie Maker Collection File (Microsoft) |
| COL | Multiplan Spreadsheet (Microsoft) |
| COL | HTML Help Collection File (Microsoft) |
| COLLECTION | Shareaza Collection (Shareaza Pty. Ltd.) |
| COLOR | Amaya Configuration |
| COM | Command |
| COM | Common Object Module |
| COM | DOS or CP/M Executable |
| COM | AOL (America Online, Inc.) |
| COM | EICAR Anti-Virus Test File (EICAR) |
| COM | Psion Organiser CommsLink Setup File (Psion PLC) |
| COMMANDLINE | Commandline Powertoy File |
| COMMON | Matlab Install File (The MathWorks) |
| COMPAT | Likely a Text File |
| CON | Knowledgeware Consolidation File |
| CON | Simdir Configuration File |
| CON | Train Simulator Train/Model Identification File (Microsoft Corporation) |
| CON | Tree Professional Conifer Creator File |
| CON | WordPerfect Document Concordance (Corel Corporation) |
| CON | Battlefield 1942 Configuration File (Electronic Arts, Inc.) |
| CON | Unreal 2 Audio File (Epic Games, Inc.) |
| CON | LucasArts Container File (LucasArts Entertainment Company LLC) |
| CON | Trace Data File (GraphiTech Ltd.) |
| CONF | IRC Related Configuration File |
| CONF | Linux Configuration File |
| CONF | Palace Server Server Configuration (Communities.com) |
| CONFIG | NET Application Configuration Information (Microsoft) |
| CONFIG | CRiSP Harvest File |
| CONSOLE | WinNT Console File |
| CONTENTSONCLIPBOARD | Contents on Clipboard Powertoy File |
| COO | Cookie File |
| COO | Fabasoft Components |
| COOL | QB - Text Analyzer Archive (Sierra Vista Software) |
| COP | Tree Professional Conifer Creator Image File |
| COR | Insight II Output Coordinate File (Accelrys Software Inc.) |
| COR | Protein Structure File |
| COR | Web GPS Correction Server Export File |
| COR | WMOVIEC Input File |
| COR | posem Correction File (Nimal Solutions Ltd.) |
| COR | Cokriging Software COREG Output File |
| CORE | Core Software Tech CORE IDC Bitmap |
| CORELPROJECT | Photo Album Project (Corel Corporation) |
| CORRECTION | As-U-Type Correction FIle (Fanix Software) |
| COS | Scarlett Expert System Compiler Query File |
| COS | Creatures Object Source (Gameware Development Ltd.) |
| COUNT | Gen Counters File |
| COUNTER | Netobjects Fusion Components Bbscomp Message File |
| COV | Fax Cover Page (Microsoft) |
| COX | Multimedia Fusion Plug-In (Clickteam) |
| CP | CompuMedic Database |
| CP | Sound Shared File |
| CP1 | Compel Show Ver 1 Presentation (Click2learn, Inc.) |
| CP2 | Compel Show Ver 2 Presentation (Click2learn, Inc.) |
| CP8 | CP8 256 Gray Scale Image |
| CPA | Colasoft Capsa |
| CPA | Cimrex Prog (Beijer Electronics) |
| CPAN | Tucows Info File (Tucows Inc.) |
| CPAO | 3dize Cool Page Objects Counter File |
| CPC | CPC Lite Cartesian Perceptual Compressed File |
| CPC | 3WayPack (The Three-Mode Company) |
| CPD | Complaints Desk Script |
| CPD | Corel PrintOffice File |
| CPD | Fax Coversheet |
| CPE | Fax Cover Sheet (Microsoft) |
| CPF | Complete PC Fax File |
| CPF | ProWORX Nxt Comment Pointer And Length File (Schneider Electric) |
| CPF | CPF Editor Contract Preparation Form Submission File (CORDIS) |
| CPF | CircuitCAM Manufacturing Process Definition File (Aegis Industrial Software Corporation) |
| CPF | Canvastic Preferences (Canvastic) |
| CPG | 3dize Cool Page File Tutorial |
| CPH | Corel PrintHouse Image |
| CPI | Calamus Graphic (invers Software) |
| CPI | Cartesian Products Compressed Internet Document |
| CPI | ColorLab Processed Image |
| CPI | Windows International Code Page (Microsoft Corporate) |
| CPIO | UNIX CPIO Archive |
| CPJ | CeQuadrant CD Project |
| CPJ | Commotion File |
| CPK | Sega FILM/CPK File Format (Sega Corporation) |
| CPL | Compel Show Ver 1 Presentation (Click2learn, Inc.) |
| CPL | Corel Color Palette (Corel) |
| CPL | Windows Control Panel Extension (Microsoft) |
| CPM | Cisco Secure Policy Manager File |
| CPM | ConceptHDL Project File |
| CPM | CP/M Executable |
| CPM | InterComm Project Manager File |
| CPM | Turbo Pascal DOS File (Borland Software Corporation) |
| CPN | Age of Empires I and II Campaign File (Microsoft) |
| CPN | Rise of Nations Campaign File (Microsoft) |
| CPN | CPN Tools CPN Model File (CPN Group at the University of Aarhus) |
| CPO | Corel Print House File |
| CPP | C++ Builder 6 (Borland Software Corporation) |
| CPP | Visual C++ Source Code File (Microsoft) |
| CPP | CA-Cricket Presents Presentation |
| CPP | Maya OpenGL 3D Scene (Alias Systems, a division of Silicon Graphics Limited) |
| CPQ | Exam Essentials Exam File (Cyber Pass Inc.) |
| CPR | Corel Presents Presentation |
| CPR | INMOS Transputer Development System Occam Program Code Fold |
| CPR | Knowledge Access Graphics |
| CPR | PV-WAVE Compiled Procedure File |
| CPR | Cubase Project File (Steinberg) |
| CPR | Patrician II |
| CPR | Port Royale |
| CPR | CPC Plus Cartridge Image |
| CPS | Antivirus Checksum |
| CPS | Central Point PC Tools Backup |
| CPS | Classroom Performance System File |
| CPS | Colored PostScript File |
| CPS | QEMM Backup of Startup Files |
| CPT | CA Cricket Presents Template |
| CPT | Corel Photo-Paint Image (Corel) |
| CPT | dBASE Encrypted Memo |
| CPT | After Shot (Corel Corporation) |
| CPT | Compact Pro Archive (Cyclos) |
| CPT | CCRYPT Encrypted File |
| CPT6 | Corel Photo-Paint Image |
| CPU | Sysoft Sandra File |
| CPX | Age of Empires I and II Campaign File (Microsoft) |
| CPX | Code Page Translation File (Microsoft) |
| CPX | Control Panel Applet |
| CPX | Corel Presentation Exchange Compressed Drawing |
| CPX | CryptaPix Encrypted Image |
| CPX | Rise of Nations Campaign File (Microsoft) |
| CPY | eCopy Scanned Document (eCopy, Inc.) |
| CPY | Atari Ramdrive CPY Commands |
| CPY | Cobol Include |
| CPY | Copy Books Data File |
| CPY | Flexus COBOL Definitions |
| CPY | RM/COBOL Development System Include File (Liant) |
| CPZ | COMPOZ Music Text |
| CPZ | CP Shrink Archive (Symantec) |
| CQ | CP/M SYSGEN Replacement |
| CQQ | Cool Quiz |
| CQS | CADfix Quality Standard (ITI TranscenData) |
| CQZ | Cool Quiz |
| CR | Crack File |
| CR | CRiSP Source Code |
| CR | Iris Printer CT Format Bitmap |
| CR$ | BASIC VB Kartei File |
| CR2 | Curious Labs Poser Character File |
| CR2 | Canon Digital Camera Raw Image Format (Canon Inc.) |
| CR4 | STABCAL (stability calculation for aqueous systems) File |
| CR5 | Tripod Data Systmes Survey Pro Coordinate File |
| CR7 | STABCAL (stability calculation for aqueous systems) File |
| CRA | Advanced Crack File (usually text) |
| CRA | Personal Craft Factory File |
| CRACKZBYMAB | YaHoE File |
| CRC | JPEG Sheriff CRC Info File (engineering bureau Office Automation) |
| CRC | Pro/ENGINEER Temporary File (PTC) |
| CRD | Windows Cardfile |
| CRD | ColdRED Script File |
| CRD | Guitar Chord File |
| CRE | Infinity Game Engine Monster Description (BioWare Corp.) |
| CRE | LiveUpdate Crescendo Catapult File |
| CREG | CrazayReg Database (Crazy-Team) |
| CRF | Calcomp Raster Bitmap |
| CRF | Database Cross-Reference File |
| CRF | MASM Cross-Reference File |
| CRF | OM2Cipher Recipient File |
| CRF | Programming Cross-reference |
| CRF | Sierra Print Artist Craft |
| CRF | System Shock 2 Archive |
| CRF | Thief 2: The Metal Age Archive |
| CRF | Thief: The Dark Project Archive |
| CRF | Zortech C++ Cross-Reference File |
| CRF | CHARTrunner Chart Definition (PQ Systems) |
| CRG | Calamus Graphic (invers Software) |
| CRH | Golf Image File (Microsoft) |
| CRH | Links Games Course File |
| CRK | Crack File |
| CRL | Certificate Revocation List |
| CRM | Capital Research Vendor Bid System |
| CRM | Netmino File |
| CRM | CHARTrunner Multi-Chart Definition (PQ Systems) |
| CRO | Webalizer.01 Lang File |
| CRP | Corel Presents Run-Time Presentation |
| CRP | dBASE Encrypted Database |
| CRP | Visual dBASE Custom Report |
| CRS | Gold Game Course File |
| CRS | Links Games Course File |
| CRS | WordPerfect 5.1 for Windows File Conversion Resource (Corel Corporation) |
| CRS | Dance With Intensity |
| CRT | Certificate File |
| CRT | Oracle Terminal Settings Info |
| CRT | UNIX Crontab File |
| CRT | Soft Concert Karaoke File |
| CRU | CRUSH Compressed Archive |
| CRV | Corel Graphics Ver. 10 Custom Gradients File (Corel) |
| CRW | Canon Digital Camera Raw Image Format (Canon, Inc.) |
| CRW | Crossword Genius |
| CRW | Cadrail Train Terrain Layout (Sandia Software) |
| CRW | CHARTrunner Workspace Definition (PQ Systems) |
| CRX | Links Games Course File |
| CRY | Crypto Chat II Encrypted Notebook-content |
| CRYPTOMITE | CryptoMite Encrypted Archive (BAxBEx Software) |
| CRZ | Links Games Course File |
| CS | Visual C#.NET Source Code (Microsoft) |
| CS | Tribes 2 Scripting File (Sierra) |
| CS | Torque Game Engine Script (GarageGames) |
| CS | Fractal Lab Data/Parameter File (Mystic Fractal) |
| CS-CNF | Currency Server Software Configuration (Cloanto Corporation) |
| CS1 | CaptureShop 1-Shot Image (Sinar) |
| CS3 | Casio WK-1800 Keyboard Output File |
| CS4 | CaptureShop 4-Shot Image (Sinar) |
| CSA | Comma Deliminated Text |
| CSA | InterComm ASCII Sheet File |
| CSA | Ultimate Ride Roller Coaster |
| CSB | CircuitSoft Viewer |
| CSB | Corel Photo-Paint Script (Corel) |
| CSB | Pci Ncr3030 Ncrflash File |
| CSC | Corel Script (Corel) |
| CSC | Wizard |
| CSC | CrystalControl LCD Control Software Screen (Crystalfontz) |
| CSD | Bitstream Fontware |
| CSD | Chemsoft MSDS Database File |
| CSD | Embroidery Design File |