.cab - Microsoft Cabinet format. Highly efficient method of compression and distribution based on Lempe-Ziv compression.

.cag - Clip Art Gallery format. Compressed picture format used to store clip art for a variety of Microsoft programs.

.cam - Casio Camera format. Native bitmap format of the Casio QV series digital camera software. ( file extension )

.cbt - Computer Based Training format. Microsoft help uses these files in the background of many Microsoft applications.

.cdf - Common Data Format. Scientific data management package that allows application programmers to manage and manipulate scalar, vector, and multi-dimensional data arrays.

.cdf - Cyberspace Description Format. ASCII-based format used for describing virtual worlds.

.cdx - Compound Index file format. Native database index file used by FoxPro. ( file extension )

.ce - Computer Eyes file format. Image files created on a DOS platform with the Computer Eyes video scanner board.

.cfg - Configuration file. Used to hold configuration information. ( file extension )

.cgm - Computer Graphics Metafile file format. Created by the American National Standards Institute as a universal metafile specification. Although originally intended to include bitmaps, these are generally not supported.

.chk - Native file format created by the MS-DOS Checkdisk program when files are fixed. These files can usually be deleted safely.

.clp - Clipboard file format. Created by Microsoft to save the contents of the Windows clipboard to disk.

.cmf - Creative Music Format. Very similar to the .midi format, except the instrument patches are stored inside the file and are designed for the FM synthesizer only.

.cnt - Content file. A file used in Windows 95 that provides the contents of help files and also points to other help files containing relevant data.

.com - Command file format. A raw binary executable with a file size of under 64K. ( file extension )

.cpp - C++ programming language file format.

.cpt - Compact Pro file format. Used for compression and archiving on Macintosh machines.

.cpt - Corel Photo Paint format. Native file format of Corel Photo Paint images.