Editing Preferred Executable Format

{{Infobox file format
| name = Preferred Executable Format
| icon = 
| extension = 
| mime = 
| type code = 
| uniform type = com.apple.pef-binary
| owner = [[Apple Computer]]
| genre = [[executable]]
| container for = [[PowerPC]] [[executable]] and [[object code]]
| contained by = 
| extended from = 
| extended to = 
| standard = 
}}
The '''Preferred Executable Format''' is a [[file format]] that specifies the format of [[executable]] files and other [[object code]]. PEF executables are also called [[Code Fragment Manager]] files (CFM).

PEF was developed by [[Apple Computer]] for use in its [[classic Mac OS]] [[operating system]]. It was optimised for [[Reduced instruction set computer|RISC]] [[central processing unit|processors]]. In [[macOS]], the [[Mach-O]] file format is the native [[executable]] format. However, PEF was still supported on [[PowerPC]]-based Macintoshes running Mac OS X and was used by some [[Carbon (computing)|Carbon]] applications ported from earlier versions for classic Mac OS, so that the same binary could be run on classic Mac OS and Mac OS X.

[[BeOS]] on PowerPC systems also uses PEF, although [[x86]] systems do not.

==See also==
* [[Comparison of executable file formats]]
* [[Fat binary]]

==External links==
* [https://web.archive.org/web/20020208214155/http://developer.apple.com/techpubs/mac/runtimehtml/RTArch-89.html PEF Structure] - documentation at developer.apple.com via web.archive.org
* [https://developer.apple.com/legacy/library/documentation/mac/pdf/MacOS_RT_Architectures.pdf Mac OS Runtime Architectures For System 7 Through Mac OS 9] - PDF from developer.apple.com (see chapter 8, PEF Structure)
* [https://web.archive.org/web/20110603204602/http://developer.apple.com/tools/mpw-tools/commandref/dumppef.html dumppef Documentation] - description of what is in a PEF file, such as allowed sections the string table.
{{Executables}}
{{Mac-software-stub}}

[[Category:Executable file formats]]
[[Category:Apple Inc. software]]