This is a few notes from reverse-engineering the pkg and mpkg format from Apple.
This is a directory. For a simple set of files, this looks as follows:
Contents/
Archive.bom
Archive.pax.gz
Info.plist
PkgInfo
Resources/
en.lproj/
Description.plist
package_version
Description of those files:
Archive.bom: bill-of-materials, made through the binary mkbom:
mkbom source_directory Archive.bomArchive.pax.gz: pax archive of the files, made with pax + cpio:
pax -w -f dest -x cpio -z .Info.plist: XML file, supported through plistlib (part of python stdlib since ?)
PkgInfo: text file with fixed content:
pmkrpkg1