File Extension 

Description 

app.config  

Dynamic properties and their values for .NET Windows applications.  

asax, ascx, asmx, aspx  

ASP.NET application files.  

bdsproj  

Project options file for BDS 2006 and earlier. Contains the current settings for project options, such as compiler and linker settings, directories, conditional directives, and command-line parameters. Set these options using ProjectOptions.  

bdsgroup  

Project group for BDS 2006 and earlier products.  

bpk  

Source file for a C++ Builder package; produces a .bpl file when compiled and linked.  

bpl  

A compiled Delphi package or a compiled C++ package (see also .dpk).  

bpr  

C++ Builder project source; when compiled, produces .exe, .dll or .ocx file.  

cbproj  

C++ project. This is not 'cproj', which is a VS.NET C++ project.  

cfg  

Project configuration file used for command line compiles. The compiler searches for a dcc32.cfg in the compiler executable directory, then for dcc32.cfg in the current directory, and then finally for projectname.cfg in the project directory. You can type dcc32 projectname on the command line and compile the project with same options specified in the IDE.  

config  

Config files contain project option information and build logic. Each project has a .config file.  

cpp  

C++ source file.  

cs  

The code-behind file for ASP.NET; also a C# source code file.  

csm  

C++ precompiled header file.  

csproj  

C# project, in keeping with MSBuild convention.  

dci  

Holds Code Insight changes you make in the IDE.  

dcp  

Contains all compile and link information for a Delphi package in the same way that a .dcu file has this information for a .pas file. Use this file if building with runtime packages.  

dcpil  

Delphi.NET compiled CLR import. Same as .dcp file for .NET.  

dcu  

Delphi compiled unit. An intermediate compiler output file produced for each Win32 unit's source code. You do not need to open these binary files or distribute them with your application. The .dcu file enables rapid compiling and linking.  

dcuil  

An intermediate compiler output file produced for each .NET unit's source code. Same as .dcu file for .NET.  

delphi.dct  

Component template changes you make in the IDE.  

dfm  

A Windows VCL form file.  

dpk  

The source file for a Delphi package. When compiled, produces a .bpl file.  

dpr  

Delphi project source; when compiled produces .exe, .dll, or .ocx file.  

dproj  

Delphi project for both native and .NET.  

dsk  

File used to save the desktop when the Autosave Project desktop option is On.  

dst  

File used to save the desktop speed setting as set in the IDE toolbar desktop combo box.  

exe  

Executable file.  

exe.incr  

Incremental build information.  

groupproj  

Project group.  

h  

C++ header source file.  

hpp  

Pascal generated C++ header file.  

i  

C++ preprocessor output (not saved by default). Each .cpp and all of its included headers are preprocessed into a .i file,  

identcache  

Information used for refactoring.  

il?  

C++ incremental linking state file.  

nfm  

A .NET VCL form file.  

nfn  

A file maintained by the Translation Tools, containing translated strings and other data displayed in the Translation Manager. There is a separate .nfn file for each form in your application and each target language.  

obj  

C++ compiled translation unit. Each .cpp and all of its included header are compiled into a resultant .obj file.  

optset  

Named option set file that stores configuration options, separately from projects.  

pas  

Delphi (Pascal) source code file.  

pdb  

Contains project debugging information for .NET.  

res, rc  

Compiled and uncompiled resource files.  

resources  

A binary resource file that can be embedded in a runtime executable or compiled into satellite assembly for .NET.  

resx  

An XML resource file containing nodes that represent objects and strings for .NET.  

rsp  

Response file used by the C++ linker.  

targets  

Targets file, an MSBuild-compliant XML file you add to your project to allow customizing the build process. It contains MSBuild scripts among other information.  

tlb  

Type library.  

todo  

The project to-do list.  

tvsconfig  

Modeling configuration file.  

txvpck, txvcls  

Information for model diagram.  

vproj  

Visual Basic projects, in keeping with VS.NET and MSBuild convention.  

web.config  

Dynamic properties and their values for ASP.NET applications.  

#nn  

#nn = #00, #01, #02, and so forth. C++ precompiled header file.