.pkg
{{Short description|Filename extension}}
{{other uses|PKG (disambiguation)}}
{{Infobox file format
| name = PKG
| extension = .pkg
| creatorcode =
| owner = Apple Inc.,
Sony Computer Entertainment,
Symbian Ltd.
| genre =
| container for = Applications
| contained by =
| extended from =
| extended to =
}}
.pkg (package) is a filename extension used for several file formats that contain packages of software and other files to be installed onto a certain device, operating system, or filesystem, such as macOS, iOS, the PlayStation Vita, the PlayStation 3, the PlayStation 4 and the PlayStation 5.
- The macOS and iOS operating systems made by Apple use .pkg extensions for Apple software packages using the Xar format internally.
- PlayStation Vita, PlayStation 3, PlayStation 4, PlayStation 5 — used for installation of PlayStation Vita, PlayStation 3, PlayStation 4 and PlayStation 5 software, applications, homebrew, and DLC from the PlayStation Store{{cite web |url=http://www.psdevwiki.com/ps3/PKG_files |title=.PKG File|publisher=PSDevWiki|accessdate= 15 March 2015}}
- System V Release 4 (SVR4) .pkg files are cpio archives that contain specific file tree structures.{{cite web|url=http://www.sco.com/developers/devspecs/gabi41.pdf|title=SYSTEM V Application Binary Interface|publisher=SCO Group|author=AT&T|accessdate= 16 March 2015}} They are software packages that can be installed, removed and tracked using the pkgadd, pkgrm, and pkginfo commands. The SVR4-based Solaris, and the Solaris-based illumos, support that package format.{{cite web|url=http://www.bolthole.com/solaris/makeapackage.html|title=How to make a Solaris package (pkg format)|publisher=Bolthole.com|author=Philip Brown|accessdate= 11 October 2013}}
- Symbian use .pkg files to store configuration information used to generate .sis installer packages.{{cite web|url=http://doc.qt.digia.com/4.6/deployment-symbian.html|title=Deploying an Application on the Symbian platform|publisher=Digia.com|author=Nokia Corporation|accessdate=15 March 2015|archive-url=https://web.archive.org/web/20140809131711/http://doc.qt.digia.com/4.6/deployment-symbian.html|archive-date=2014-08-09|url-status=dead|df=}}
- BeOS used .pkg files as part of their software packaging platform. The package format was used after Be Inc. bought Starcode Software Inc. and acquired their packaging tools.{{cn|date=April 2020}}
- Apple Newton operating system used files ending in .pkg for Newton applications and software. As a result, when seen from the Mac OS X Finder, Newton applications appear the same as Mac OS X Installer packages, however they do not share their file format.{{cn|date=April 2020}}
- PTC/CoCreate 3D Modeling application use .pkg files to store model files. This .pkg file uses the ZIP file format.{{cn|date=April 2020}}
- Microsoft is said to use .pkg files for profile storage on Xbox Network.{{cn|date=April 2020}}
- L3 Avionics systems use some .pkg files for software updates.{{cn|date=April 2020}}