.??_ Files ending in "_" are often compressed install files of the same
name (e.g., .EX_ expands to .EXE, .DL_ expands to .DLL, etc.)
.C C Program File
Check Point Site Configuration for Secure Remote
UNIX Compact File Achive
Desktop Color Separation Specification Cyan Layer (usually an EPS file)
.C?? Winace Compressed File (open with WinRAR)
.C++ C++ Source Code
.C-- Sphinx C-- Source
.C00 Ventura Print File
.C01 Typhoon Wave File
.C08 Lord Of Destruction Game File (unverified)
.C2D IsoBuster File
WinOnCd CD Image
.C3D Chem3D Chemical File
.C3T Chem3D Chemical Template File
.C4 JEDMICS (Joint Engineering Data Management) DoD Engineering Data Format [For-pay Viewer]
Edmics [XnView]
.C4D Cinema 4D (3D Modeling texturing and animation program)
.C6 Ashlar-Vellum File
.C86 C86 C Program
.C-- Sphinx C-- Source code
.CA Telnet Server Initial Cache Data File
DATAIR FlexPlus Data File
.CA1 OzWin CompuServe E-mail/Forum Access Catalog File
STABCAL (stability calculation for aqueous systems) File
.CA2 STABCAL (stability calculation for aqueous systems) File
.CA4 Electronics Workbench Circuit
STABCAL (stability calculation for aqueous systems) File
.CA7 Beta 44 Job File
STABCAL (stability calculation for aqueous systems) File
.CAB Cabinet File (Microsoft installation archive)
Install Shield v5.x or 6.x Compressed File (not compatible with MS .CAB files)
.CAC dBase IV Executable File
.CAD Softdesk Drafix CAD File
.CAF Southern Company Terrestrial Data Acq
.CAG MS Clip Gallery Catalog File
.CAL SuperCalc Worksheet
Calendar File
HTML Calendar Maker Pro
DOS Calendar Creator File
Cals Raster File [SwiftView]
Radiance Function File Format
CALS Raster [XnView]
.CALS CALS Raster [XnView]
.CAM Casio Camera Graphic [XnView] [IrfanView]
Camtasia Project/Producer Files (screen recording editor)
.CAN Canon Navigator Fax [XnView]
.CAP Ventura Caption
Network Associates Sniffer Capture File
Telix Session Capture
Compressed Music File
.CAR AtHome Assistant File
Carrara Environment
NeoBook Cartoon [XnView]
.CAS Comma-delimited ASCII File
i2's Case Notebook Timeline Analysis
Casio Program
.CAT dBase Catalog
Quicken IntelliCharge Categorization File
Cognos Impromptu Database Report
OzWin CompuServe E-mail/Forum Access Catalog File
Photomatrix PhotoStudio Graphic [XnView]
.CAZ Computer Associates Archive
.CB MS Clean Boot File
Crystal Button File
Brief Macro Source Code
.CBC CubiCalc Fuzzy Logic System File
.CBH ChessBase Chess Database File
.CBI IBM Mainframe Column Binary Formatted File
.CBL COBOL Program
Contextual Browsing Language Viewer (usually JavaApplet)
.CBM XLib Compiled Bitmap
Fuzzy Bitmap [XnView]
.CBT Computer Based Training
.CC C++ Program File
Visual dBASE Custom Class File
dB2K Custom Class File
Picture Window's Color Curve File (ASCII text file)
.CC1 Chem3D Cartesian Coordinates 1
Briggs Softworks Calendar Commander
.CC2 Chem3D Cartesian Coordinates 2
.CC5 Calendar Creator 5.x 6.x File
.CCA CC:Mail Archive File
Multimedia Fusion File (multimedia game creation)
.CCB Visual Basic Animated Button Configuration
.CCC Chat
Curtain Call Native Bitmap Graphic
.CCD CloneCd Related File [Fantom CD Emulator]
Vector CAD Program File
.CCE Calendar Creator 2 Event File
.CCF OS/2 Multimedia Viewer Configuration File
Symphony Communications Configuration File
Remote Control File (various to include: ProtoProEdit, RAVedit)
AudioReQuest Control File
.CCH Corel Chart
Fabasoft Components
.CCL Intalk Communication Command Language
.CCM Lotus CC:Mail Mailbox
.CCN Vitalize! Game File [Played via IE plug-in]
.CCO CyberChat Data File
XBTX BTX Graphics File
.CCP C Converter Profiles (construction site management)
.CCR Chat Room Shortcut
.CCS CONKY CeZaR Stribas International
.CCT Macromedia Director Shockwave Cast
Logic Works Schematic File
SIL Hebrew Font System Transliteration Table
.CCX Corel Compressed Exchange File
.CD cdTree Content List
.CD1 DATAIR Cafeteria Document System Data File
.CD2 DATAIR Cafeteria Document System Custom Text File
.CDA CD Audio Track
.CDB Turbo C Database
Clipboard File
One Page from a ROM With a View Project File
CardScan Database
Nokia 9210/9290 Contact Database (Nokia runs Symbian)
SymbianOS Contact Database File
PowerDesigner Conceptual Model Backup File
.CDC Chromeleon Driver Configuration Plugin
Nero File (CD burning/design software)
.CDD Chromeleon Device Driver
Claris Draw v 1.2 Document
.CDE Honeywell Hybrid Control Designer (HC900-x Industrial Controllers)
.CDF Comma Delimited Format
Cyberspace Description Format
MS Channel Definition Format
InstallShield Components Definition File
NetCDF Graphic File
.CDG DART Karaoke Studio CD+G File (contain only song lyrics and synchronization data)
.CDI Phillips Compact Disk Interactive Format
Disc Juggler File (CD-ROM data)
.CDJ Disc Juggler File (CD-ROM data)
.CDK Atari Calamus Document
.CDKEY Protocol Used in Communicating from MediaRemote Server to PC MediaRemote Plug-in (ASCII text)
.CDL CaseWare Working Papers Document Link
SignLab Vector Graphic
.CDM PowerDesigner Conceptual Model File
Visual dBASE Custom Data Module
.CDP CD/Spectrum Pro
.CDR Corel Vector Graphic Drawing [XnView]
Raw Audio-CD Data
Sound File [Linux Player]
.CDS ChemDraw Stationery Document
.CDT Corel Draw Template
STABCAL (stability calculation for aqueous systems) File
.CDU CDU Paint [XnView]
.CDX Compound Index [File Structure]
Corel Draw Compressed Drawing
MS Visual Foxpro Index
Active Server Document
ChemDraw Chemical Structure
Microstation Cell Library Index
.CDXL Old Amiga Movie Format
.CDXML ChemDraw XML ChemDraw Format
.CDZ ROM With a View Project File
.CE FarSide Computer Calendar File
Computer Eyes, Digital Vision [XnView]
.CE1 Computer Eyes, Raw [XnView]
.CE2 Computer Eyes, Raw [XnView]
.CE3 Calendar Creator 3.x 4.x Event List
.CEG Continuous Edge Graphic
Tempra Show Bitmap Graphic
.CEL Autodesk Animator Graphic
CIMFast Event Language File
Kiss Paper Doll File
Microstation Cell Library
Kiss Cel [XnView]
Lumena CEL [XnView]
.CEM Empire Earth Game File
.CEN Master Tracker Financial Analysis
.CER Certificate File
Sierra Print Artist Certificate
.CEV Software License Tracking Tool (CERTAUTH.CEV)
LOUT Character Encoding File (High-Level Language For Document Formatting)
.CEX The Currency Exchanger Rate File
INMOS Transputer Development System Occam User Program
ThumbsPlus File (Progressive Multi-image JPEG file)
.CF Imake Configuration File
.CF4 Catfish File Manager Support File
.CFB Comptons Multimedia File
.CFC Cold Fusion File
.CFF Capabilities File for FOUNDATION(tm) Fieldbus H1 (31.25 kbit/s)
.CFG Configuration (various)
.CFH Capabilities File for FOUNDATION(tm) Fieldbus HSE (100 Mbit/s)
.CFL Corel Flowchart File
.CFM Corel FontMaster
Cold Fusion Template File
Visual dBASE Windows Customer Form
.CFN Atari Calamus Font Data File
.CFO TCU Turbo C Utilities C Form Object
.CFP Complete Fax Portable Fax File
.CFR IBM Configurator Report (if you don't have the program ask the sender to export to .RTF for you)
.CFW ChemFinder Form
.CGA Ventura CGA Screen Characters
.CGI Common Gateway Interface Script
.CGM Computer Graphics Metafile
.CGP NetCaptor CaptorGroup
.CH Clipper Header
OS/2 Configuration File
.CH3 Harvard Chart (Harvard Graphics taken over by Serif)
.CH4 Charisma 4.0 Presentation
.CHA Adobe Pagemaker Kerning Data
.CHAT PIRCH98 Chat File
.CHD FontChameleon Font Descriptor
ChartFX File
.CHF pcAnywhere Remote Control File
.CHI Chiwriter Document
Help File Index (typically used when the Help file will stay on a CD-ROM -- .CHI speeds access to the info)
.CHJ Help Composer Project
.CHK CHKDSK/SCANDISK Output
WordPerfect Temp File
.CHL Chromeleon Channel Raw Data
Configuration History Log
.CHM Compiled HTML Help
ChemDraw Chemical Structure (old format)
.CHN Ethnograph Data File
.CHP Ventura Publisher Chapter
.CHQ Help Combined Full-text Search File (produced when multiple .CHM files are merged)
.CHR Character or Font File
.CHS Corel WP Chart Style
ATI Radeon Video Driver File
.CHT Cheat Machine Data File
ChartViewer dBase Interface File
Harvard Graphics Vector File (Harvard Graphics taken over by Serif)
ChartFX Template File
.CI CitectSCADA File
.CIF Ventura Chapter Information
CalTech Intermediate Graphic
Easy CD Creator Image
pcAnywhere Caller File
Ventura Converted Image File
Colombo Ipermedia File
Chip Layout Information
Crystallographic Information File
.CIL Clip Gallery Download Package
.CIM Sim City 200 File
CompuApps Drive Backup Image
CIMEX Cimpack Design Drawing File
.CIN OS/2 Change Control File
Cinetitler Digital Screen Subtitling
Kodak Cineon [XnView]
.CIP Ghost Keylogger File
.CIR SuperMax E-CAD Save-File Command
PSpice File
Flash Color Table
.CIS CheckInbox File
.CIT Intergraph Scanned Image [XnView]
.CIX TCU Turbo C Utilities Database Index
.CK1 iD/Apogee Commander Keen 1 Data File (.CK1 to .CK6)
.CKB Borland C++ Keyboard Mapping File
.CKD CADKEY GraphX File Format (ver 2 and above)
.CKP Ingres Checkpoint File
.CKT Crocodile Clips (Electronic design/physics)
.CL Generic LISP Source Code
.CL3 Easy CD Creator Layout File
.CL4 Easy CD Creator Layout File
.CL5 Easy CD Creator Layout File
.CLA Java Class File (usually .CLASS but can be shortened)
CLARION for DOS
.CLASS Java Class File
.CLB ICQ Contact List
MS Office XP Developer Code Librarian
cdrLabel Compact Disc Label
.CLF ListPro File
.CLG Disk Catalog Database
Maxagrid CTM Log File (text format)
.CLK Corel R.A.V.E. Animation File
.CLL Crick Software Clicker File
OzWin CompuServe E-mail/Forum Access Custom Library Search
.CLO Cloe Ray-Tracer [XnView]
.CLOE Cloe Ray-Tracer [XnView]
.CLP Windows Clipboard/Picture [IrfanView]
Quattro Pro Clip Art
CLIPS/wxCILPS File (C Language Integrated Production System)
Clipper 5 Compiler Script
PC Paint/Pictor Page [XnView]
GoDot [XnView]
.CLR WinEdit Colorization Word List
1st Reader Binary Color Screen Image
PhotStyler Color Definition
FileMaker Spelling Dictionary
.CLS Visual Basic Class Module
C++ Class Definition
.CLV Aladdin Knowledge Systems Vbox Current Language File (software distribution)
.CLW Microsoft Visual C++ Class Wizard File
CLARION Database (DOS & Windows) [CLARION Magazine]
.CM Craftman Data File
.CM2 Curious Labs Poser Camera File
.CM4 ClipMate Data File
.CMA Applix TM1 Database File (text)
.CMB Chromeleon Backup Archive
.CMC PowerFront File (part of ShopMind)
.CMD OS/2, WinNT Command File
DOS CP/M Command File
dBase II Program File
1st Reader External Command Menu
.CMF Creative Music File
Corel Metafile
.CMG Chessmaster Saved Game
.CMK Card Shop Plus File
.CML Cheat Machine Library File (Windows)
PADGen Company Info File
.CMM CEnvi (ScriptEase:Desktop) Batch File
.CMO Virtools Behavioral Server Composition
.CMP Leadview Bitmap
Discorp CMP Image [XnView]
Open Access File
Address Document
JPEG Bitmap
CorelDRAW Postscript Printer Header
Route 66 Address Document
MS Word for DOS User Dictionary
.CMQ Culturemetrics (Personality Profile Analyser)
.CMR MediaPlayer Movie
.CMT Culturemetrics (Personality Profile Analyser)
Chinon ES-1000 Digital Camera [XnView]
.CMU Carnegie Mellon Univeristy Stereo Raster Image
CMU Window Manager [XnView]
.CMV Corel Move Animation
.CMW MS Custom Maintenance Wizard File
COM-Watch (data analyser)
.CMX Corel PhotoPaint Image [XnView]
Corel Presentation Exchange Image [XnView]
The Sims (Maxis) 3D Body Mesh Data
Apple Viewer File
.CNC CNC General Program Data
Click 'n Create File
.CND ControlDraw File
Embroidery Design File [possibly read with Melco Sizer Software]
.CNF Configuration (various)
SpeedDial
.CNM Windows Application Menu Options and Setup File
.CNQ Compuworks Design Shop File
.CNREG EULANDA® Warenwirtschaft (ERP) Configuration Information
.CNREP EULANDA® ERP System Report Template
.CNS W2K Client Connection Manager Export File
.CNT Help File Contents (and other contents needs)
.CNV MS Word Data Conversion File
WS_FTP Pro Upload Conversion File Data
WordPerfect Temporary File
Canvas versions 6, 7, 8
.CO Cult3D ActiveX Player Application
.COB COBOL Program File
Caligari Truespace Format
TrueSpace2 Object
.COD Code List
Compiler Program Code
.COD Multiplan Data File
dBase Template Source File
SWAT Input Control File (river basin scale model)
FORTRAN Compiled Code [FORTRAN]
Video Text File
.COK Carmageddon Patch File
.COL Autodesk Color Palette
Multiplan Spreadsheet
Lotus Notes Import Column Description File
.COM Command (Executable file)
.COMPAT Likely a text file (e.g., README.COMPAT)
.CON Knowledgeware Consolidation File
Tree Professional Conifer Creator File
Simdir Configuration File
.CONF IRC Related Configuration File (IRCDs or EggDrops)
Linux Configuration File (also UNIX)
.CONFIG MS .NET Application Configuration Information
.COO Fabasoft Components
.COP Tree Professional Conifer Creator Image File
.COR Protein Structure File
Web GPS Correction Server Export File
WMOVIEC Input File
.COS Scarlett Expert System Compiler Query File (Scarlett is not presently available)
.COV Fax Cover Page (Win2000 Cover Page Editor)
.CP CompuMedic Database (medical billing software)
.CP8 CP8 256 Gray Scale Image [XnView]
.CPA Colasoft Capsa (network sniffer)
.CPD Fax Coversheet
Corel PrintOffice File
Complaints Desk Script
.CPE Fax Coversheet
.CPF Complete Fax File
.CPG 3dize® Cool Page File
.CPH Corel Print House Image
.CPI Code Page Information
ColorLab Image
Calamus [XnView]
.CPJ CeQuadrant CD Project
Commotion File (compositing software tool)
.CPL Control Panel Extension
Corel Color Palette
Compel Presentation
.CPN Age of Empires II Campaign File
.CPO Corel Print House File
.CPP Borland C++ Builder 6
CA-Cricket Presents Presentation
Maya File
.CPR Corel Presents Presentation
Knowledge Access Graphics
INMOS Transputer Development System Occam Program Code Fold
.CPS Antivirus Checksum File
Central Point PC Tools Backup
Colored PostScript File
Classroom Performance System File
.CPT Macintosh Compressed File
Corel Photo-Paint Image [XnView] [IrfanView]
Jasc After Shot (Image Expert 2000 taken over by Jasc from SierraImaging)
dBase Encrypted Memo
CA Cricket Presents Template
.CPT6 Corel Photo-Paint Image [IrfanView]
.CPX Control Panel Applet
Code Page Translation File
CryptaPix Encrypted Image
Corel Presentation Exchange Compressed Drawing
.CPY Copy Books Data File
Atari Ramdrive CPY Commands
Flexus COBOL Definitions (function, element and value properties associated with a control)
.CPZ COMPOZ Music Text
.CR CRiSP Source Code
.CR2 Curious Labs Poser Character File
.CR4 STABCAL (stability calculation for aqueous systems) File
.CR7 STABCAL (stability calculation for aqueous systems) File
.CRA Personal Craft Factory File (no longer supported--GraphicCorp bought by Corel)
.CRD Cardfile (Windows 3.x Database)
Guitar Chord File [On-line Guitar Archive] (Usually an ASCII text file)
.CRF Zortech C++ Cross-Reference File
Database Cross-Reference File
OM2Cipher Recipient File
Sierra Print Artist Craft
System Shock 2 Archive [Dragon UnPACKer]
Thief 2: The Metal Age Archive [Dragon UnPACKer]
Thief: The Dark Project Archive [Dragon UnPACKer]
.CRG Calamus [XnView]
.CRH MS Golf Image File
Links Games Course File
.CRK Crack File (differences between original and cracked files) [Need proper version of CRK.EXE to open]
.CRL Certificate Revocation List
.CRM Capital Research Vendor Bid System
.CRP dBase Encrypted Database
Visual dBASE Custom Report
Corel Presents Run-Time Presentation
.CRS WordPerfect 5.1 for Windows File Conversion Resource
Links Games Course File
Gold Game Course File
.CRT Certificate File
Oracle Terminal Settings Info
UNIX Crontab File (not a required extension for Crontab)
.CRU CRUSH Compressed Archive
.CRW Canon Raw Format (Image) [XnView] [ACDSee 4.0]
.CRX Links Games Course File
.CRY Crypto Chat II Encrypted Notebook-content
.CRZ Links Games Course File
.CS C#.NET Source File
.CSA Comma Deliminated Text
Ultimate Ride Roller Coaster
.CSB Corel Photo-Paint Script
CircuitSoft Viewer (a module of EMSI Complete) - (Unverified)
.CSC Corel Script
.CSD Bitstream Fontware File
Chemsoft® MSDS Database File
Embroidery Design File [possibly read with Melco Sizer Software]
.CSF Van Dyke's CRT/SecureCRT Script File
GeoMedia Coordinate System File
.CSG Statistica Graph File
.CSH Hamilton Labs C Shell Script File
.CSI Cyberautograph Signed Item
.CSK Claris Works
.CSM Borland C++ Symbol File
Borland C++ 4.5 Precompiled Header
Kodak DC265 Camera Script
.CSN Dreamweaver MX's Snippet
.CSP PC Emcee On-Screen Image
CaseWare Working Papers Script Page
.CSQ Foxpro Queries
.CSS Hypertext Cascading Style Sheet
Stats+ Datafile
Statistica Datasheet
.CST Macromedia Director Cast File
.CSV Comma-Separated Variables
CompuShow Adjusted EGA/VGA Palette
.CT Scitex CT Handshake Bitmap [XnView]
Iris CT Graphic [XnView]
.CT0 Maxagrid CTM File Being Processed (text format)
.CT1 Maxagrid CTM File Successfully Processed (text format)
.CT2 Maxagrid CTM File Unsuccessfully Processed (text format)
.CTB NoteTab Clipbar
.CTC PC Installer Control
.CTD Cobra Track Dump (COmBined Reconstruction for Atlas)
Cardtable File (text file)
Marine Data File (e.g., automatic float data)
Simpsons Cartoon Studio Export File
.CTF TIFF Compressed File
WhereIsIt Catalog
Symphony Character Code Translation
MGI PhotoSuite 1.0/8.0 Album File
Calculator Text Format
.CTG Cartridge Definition File
ChessBase Opening Book
Canon Powershot Pro 70 Info File
.CTL Setup Information (various)
User Control (various)
.CTM FreeBSD Content Management File
Java Charge Transaction Matrix File
Crazytalk Talking Animation File
Maxagrid CTM File (text format)
SDR99 Speech Recognition Task Time Marked Conversation Input
Content Delivery Service (Web site pending as of Feb 2002)
.CTP American Greetings Greeting Cards
ChemDraw Template
.CTT Hotmail List of E-mail Contacts
LabView File
.CTX Compressed Text
Visual Basic User Control Binary File
Pretty Good Privacy (PGP) Ciphertext File
MS Online Course Text
Chinese Character Input File
.CTY SimCity City File
.CUB OLAP Cube File (definition for SQL Server, any OLE DB, or ODBC-compliant database)
.CUE MS Cue Cards Data
Description File for a CD-Image [Fireburner.com or Goldenhawk.com] or [Fantom CD Emulator]
.CUF Turbo C Utilities Form Definition
.CUL IconForge/ImageForge Cursor Library
.CUP OzWin CompuServe E-mail/Forum Access Catalog Library Update
.CUR Cursor Microangelo [IrfanView]
.CURSOR Sun Icon/Cursor [XnView]
.CURXPTHEME Cursor XP File (changes look & function of mouse cursor)
.CUT Dr. Halo Bitmap Graphic [XnView]
INMOS Transputer Development System Occam Utility Package
Utilitaires (multiple utilities)
.CV Corel Versions Archive
MS CodeView Information
.CV4 Codeview Colors
.CV5 Canvas version 5
.CVA Compaq Diagnostics
.CVG Image File
.CVP WinFax Cover Page
Portrait [XnView]
.CVR WinFax Cover Sheet
ElectraSoft Fax Cover Sheet
.CVS Canvas Drawing File
Outlook Express File
Sound File [Linux Player]
.CVT dBase Converted Database
.CVW Codeview Colors
.CW3 Crossword Construction Kit Puzzle Group
Claris Works Win 3 Document (now Filemaker)
Chem Draw Molecular Structure (Lewis structures, orbitals and lab apparatuses)
.CWB WebNote Document
.CWD StarDraft CWAD File (StarCraft Editor)
.CWE Crossword Express
.CWK Claris Works Data also see AppleWorks
.CWS Claris Works Template also see AppleWorks
.CWW Crossword Weaver File
.CXE Common XML Envelope
.CXT Macromedia Director Protected Cast File
Vegas Jackpot Gold Game Data File
.CXX Zortech C++ Program
.CYN Cynex Root55 Program Extension
.CYP Cypherus Encrypted Archive
