| comb | Amazon Lumberyard Blend Space Combination Data |
| comp | CodeWarrior Compiler Data |
| conc | Concurnas Source Code |
| container | Eclipse IDE Project Settings Data |
| cord | Visual Studio Cord Data |
| core | Linux Core Dump Data |
| cos | Scarlett Expert System Compiler Query Data |
| cos | Scilab Binary Diagram |
| cosf | Scilab ASCII Diagram |
| counter | NetObjects Fusion Components Bbscomp Message |
| coverage | Visual Studio Code Coverage Data |
| coveragexml | Visual Studio Code Coverage XML Data |
| cox | Click and Create Extension Object |
| cp | CPIde Source Code |
| cp | Xcode C++ Source Code |
| cpb | CPB Data |
| cpd | WebDev Code Style Data |
| cpdsc | CMSIS Pack Project Description |
| cpf | Cab Provisioning Format |
| cpf | ProWorx NXT Comment Pointer Data |
| cphd | CloudChan Pre-processed Hypertext Document |
| cpj | CUDA Project |
| cpk | Novell Netware Compiled Server Software Package |
| cpk | WDK Driver Test Manager Log |
| cpl | Concordance Desktop Programming Language Script |
| cplist | GNU Make C Property-list Data |
| cplz | Crestron SIMPL# Pro Library |
| cpp | Xcode C++ Source Code |
| cpr | Transputer Development System Occam Program Code |
| cpt | Concordance Compiled CPT Script |
| cpy | COBOL Include Data |
| cpz | Crestron SIMPL# Pro Program |
| cpz | LoseThos C+ Source Code |
| cr | CRiSP Macro File |
| cr1 | CRBasic Source |
| crash | Mac OS X Crash Log |
| crev | Adobe Captivate Commentable SWF |
| crf | MASM Cross-Reference Data |
| crf | µVision Cross-Reference Data |
| crn | Crunch Compressed Texture |
| crp | dBASE IV Encrypted Database |
| crp | Visual dBASE Customer Report Data |
| cryproject | CryENGINE Project |
| cs | CLEO Custom Script |
| cs | Visual C# .NET Class |
| csc | Ovation Pro C Script |
| csdef | Microsoft Azure Service Definition Schema |
| csdl | Conceptual Schema Definition Language Data |
| csgrad | Visual Studio Gradients Data |
| csh | CSH Shell Script |
| cshader | Visual Studio CShader Data |
| cshtml | Razor C# Web Page |
| csi | ContentServ CS EMMS Include |
| csi | CR10X EdLog Source Code |
| csig | SCons Content Signature |
| csl | Citation Style Language Document |
| cslog | CodeSite Log |
| csm | C++ Builder Precompiled Header |
| csn | Adobe Dreamweaver Code Snippet Data |
| csn | Dreamweaver Code Snippet File |
| cso | High Level Shader Language Compiled Bytecode |
| csp | CaseWare Working Papers Script Page |
| csp | InterSystems Cache Server Page |
| csp | RadGs Concept Server Page |
| csp | SAP Business Objects Crystal Server Page |
| cspkg | Microsoft Azure Service Package |
| csq | Microsoft Visual FoxPro Client-Server Query File |
| cst | ContentServ CS EMMS Template |
| csx | Visual C# Script |
| ctc | Visual Studio Command Table Configuration |
| ctf | MATLAB Component Technology File |
| ctl | PDP-10 Batch File |
| ctl | Visual Basic User Control Text |
| cto | Visual Studio Binary Command Table Output |
| ctp | BestAddress HTML Editor Combined Template |
| ctp | CakePHP Template |
| ctrace | Android System Trace Data |
| ctrl | Oracle WebLogic Workshop Controls |
| cts | ABC Permanent Locations Data |
| ctsym | Visual Studio Command Table Symbols File |
| ctx | Visual Basic User Control Binary Data |
| ctxt | BlueJ Context File |
| cu | CUDA Source Code |
| cuf | Turbo C Utilities Form Definition |
| cuh | CUDA Header |
| cuo | CUDA Object |
| curl | Curl Applet |
| cus | ConciseURI Syntax Data |
| cv | Microsoft CodeView Data |
| cv4 | Microsoft CodeView Graphics Data |
| cvb | Borland Database Engine Internationalization Data |
| cvip | NI LabWindows/CVI Profiler Data |
| cvsignore | CVS Ignore File |
| cvsrc | CVS Configuration Data |
| cvsrc | TortoiseCVS CVS Commands File |
| cwlink | CodeWarrior Link Data |
| cwm | IBM WebSphere Map Designer Express Map Definition |
| cwproj | C Omega Project |
| cwproj | Clarion 7 Project |
| cx | Codemapper Script |
| cy | Cycript Source Code |
| d | D Source Code |
| d | Dialect Source Code |
| d | GCC Dependency File |
| d2wmodel | WebObjects Web Script |
| d4 | Dataphor Source Code |
| d43 | IAR System MSP430 Debug Data |
| d4c | Dataphor Catalog Data |
| dabriefcase | RemObjects Data Abstract File Briefcase |
| daconfig | RemObjects Data Abstract Configuration |
| daconnections | RemObjects Data Abstract Connections Data |
| dacpac | Microsoft SQL Server Data Tier Application Package |
| dad | RemObjects Delphi Data Abstract Driver |
| dadiagrams | RemObjects Data Abstract Data Diagrams |
| dadx | Eclipse Document Access Definition Extension |
| dart | Dart Source Code |
| das | Atari Jaguar DSP Assembly Source |
| daschema | RemObjects Data Abstract Schema |
| dat | GameMaker Studio Audio Data Package |
| datasource | Microsoft Visual Studio Data Source |
| db | Atari Jaguar Debugger Script |
| db2sp | Visual Studio DB2 Create Procedure Statement Data |
| db2tbl | Microsoft Visual Studio DB2 Table Script |
| db2tr | Microsoft Visual Studio DB2 Trigger Script |
| db2udf | Visual Studio DB2 User Defined Function Data |
| db2vw | Microsoft Visual Studio DB2 View Script |
| dba | Amazon Lumberyard Animation Database |
| dba | CryENGINE Animation Data |
| dba | DarkBASIC Source Code |
| dba | Visual Prolog Database |
| dbag | WinSQL DataBag Data |
| dbd | Modula-2 Debug Data |
| dbf | Alpha Five Table Data |
| dbf | Microsoft Visual FoxPro Database Table |
| dbg | IAR System XLink Debug Data |
| dbg | Microsoft Visual Studio Debug File |
| dbgdt | IAR System Debugger Desktop Data |
| dbgsym | Pidgin IM Debug Symbols Data |
| dbi | Data Explorer Information |
| dbk | DocBook Source Code |
| dblink | Altium Designer Database Link |
| dblog | Debugview++ Debug Log |
| dbml | Database Markup Language File |
| dbnml | NML Language Database Extension |
| dbo | DarkBASIC Object |
| dbo | dBase IV Compiled Program |
| dbp | Visual Studio Database Project |
| dbproj | Visual Studio 2010 Database Project |
| dc | Dialect Compiled Code |
| dc | Xilinx ISE Synopsys Setup Data |
| dcd | Fortran DCD Data |
| dcf | D-LIB Generic Bytecode |
| dcf | Dyalog APL Component File |
| dcf | ProWorx NXT Database Configuration |
| dci | RAD Studio Delphi Code Insight |
| dci | Tally.ERP 9 Base Dictionary |
| dcl | Delphi Component Library |
| dcp | Delphi Component Package |
| dcpil | Delphi Compiler Symbolic Information Data |
| dcr | Delphi Component Resource |
| dct | Delphi Component Template |
| dct | Tally.ERP 9 Dictionary Data |
| dct | Visual FoxPro Database Container Memo |
| dcu | Delphi Compiled Unit |
| dcuil | Delphi .NET Compiled Unit |
| dcurl | Curl Detached Applet |
| dcw | Tally.ERP 9 Working Dictionary |
| dcx | Visual FoxPro Database Index |
| dd | DataFlex Data Dictionary |
| dd | Visual Studio Deployment Diagram |
| dd64 | x64dbg Data |
| dda | GLBasic ASCII Scene Data |
| ddb | ProWorx NXT Descriptor Data with Blocking |
| ddb | Transputer Development System Occam Debugging Info |
| ddd | Alpha Five Data Dictionary |
| ddd | GLBasic 3D Data |
| ddf | Diamond Directive File |
| ddf | IAR System C-SPY Device Description Data |
| ddf | ProWorx NXT Descriptor Data File |
| ddif | Tally.ERP 9 Metadata |
| ddl | Data Definition Language File |
| ddm | Alpha Five Data Dictionary Memo |
| ddp | Delphi Diagram Portfolio |
| ddr | FileMaker Pro Database Design Report |
| dds | Amazon Lumberyard DirectDraw Surface Data |
| ddt | WinSQL Data Diff Template |
| ddw | GLBasic World File |
| ddx | Alpha Five Data Dictionary Index |
| dec | VersaPro Declaration File |
| dectest | Python Decimal Arithmetic Based Test Cases Data |
| def | C++ Definition File |
| definition | Apple Automator Data Type Definition |
| defs | BlueJ Settings File |
| dem | Creator Simulator Temporary Data |
| dem | Delphi Edit Mask |
| dem | Turing DEM File |
| deo | Creator Simulator Compiled Module |
| dep | IAR System Dependency Data |
| dep | Visual Studio Package and Deployment Wizard Dependency File |
| dep | WinDev Dependency Data |
| dep | µVision Dependency Data |
| depend | Code::Blocks Dependencies File |
| deployproj | RAD Studio Deployment Manager Configuration |
| des | Creator Simulator Mozart Source Code |
| developerprofile | Xcode Developer Profile Data |
| dex | Android Compiled Executable |
| df | OpenEdge ABL Data Definition |
| df1 | Omnis Native Data File |
| df4 | Omnis Studio Database File |
| df6 | Omnis Studio v6 Database |
| dfac | DreamFactory ActiveX Control |
| dfd | ABC Dyadic Functions Data |
| dfm | Delphi Form |
| dfn | Delphi Definition File |
| dft | Dyalog APL Format Data |
| dg | DataFlex Dialog Box Source Code |
| dg5 | DGLux5 Page |
| dgd | DGD Program |
| dge | Micro Focus Studio Declaration Generator Batch File |
| dgml | Directed Graph Markup Language Document |
| dgrp | Retro Studios Dependency Group |
| dgsl | Directed Graph Shader Language Data |
| dgx | IBM Rational XDE Diagram |
| di | D Language Source Code |
| diagsession | Microsoft Visual Studio Diagnostic Session Data |
| dic | WebDev Dictionary Data |
| dif | ProWorx NXT Data Interchange File |
| dill | Dart Compiled Binary |
| din | DataEase Installation Script |
| din | Dyalog APL Input Table |
| dip | Crestron SIMPL IP Table Data |
| dir | WebSTAR Directory Indexer Plugin |
| dis | DisSharp Project |
| disco | Visual Studio .NET Discovery Data |
| discomap | Visual Studio .NET Discovery Map Data |
| discordbot | Discord Bot Maker Project |
| dj | DJGPP Source Code |
| djg | DJGPP Makefile |
| dlct | AppleScript Dialect Data |
| dldi | libfat Dynamically Linked Device Interface |
| dlf | Dyalog APL Session Log |
| dlg | RadASM Dialog Data |
| dlg | Visual C++ Dialog |
| dlk | Transputer Development System Occam Compiler Link Info |
| dm | BYOND Dream Maker Source Code |
| dm1 | ER/Studio Data Model |
| dm2 | Toad Data Modeler 2 Data |
| dmb | BYOND Dream Maker Compiled World |
| dmd | Domain Model Definition |
| dmd | Visual dBASE Data Module |