51 bytes added, 17:41, 19 April 2020
fix Dengwiki link, add pk7, minor tweaks
'''PK3''' is an alternate extension for {{wp|ZIP Zip (file format)|ZIP files}}. This nomenclature was introduced by {{wp|Quake III Arena}}. However, contrarily to the PAK format used by [[Quake]] and [[Wikipedia:Quake II|Quake II]], PK3 is not its own format, but merely a naming trick to prevent the operating system from associating these files with "virtual folders" or archiving software, and to avoid leading users to believe they have to extract the content to make the game work. The PK7 variant uses {{wp|7-Zip}} compression.
Several [[source port]]s have adopted support for using PK3 instead of, or in addition to, [[WAD]] files to distribute mods. But unlike WAD files (which have standardized marker lumps such as P_START/P_END or F_START/F_END for various lump types), there are no cross-port standards for how data should be organized when placed in a PK3 file.
==Folder structure==
Since the ZIP format imitates a filesystem file system with a tree hierarchy, the differences between the various implementations of "PK3" files reside mostly in the folder structure to which a PK3 mod should conform.* [[Doomsday]] and [[Risen3D]] use a model detailed {{dengwiki|PK3fs/pk3|here|linkonly=1}}.* [[Eternity Engine|Eternity]] uses a model mostly compatible with ZDoom's, detailed {{eterwiki|ZIP|here|linkonly=1}}. A .pke PKE extension is recommended for Eternity-specific modifications.
* [[EDGE]] also uses a model mostly compatible with ZDoom's, detailed {{edgewiki|Using ZIPs as WAD replacement|here|linkonly=1}}. An .EPK (Edge PaK) zip extension is recommended for EDGE-specific modifications.
* [[Vavoom]] has a model inspired from the approach used in the [[Quake]] series or [[Doom 3]].