Open an OS X PKG file

crack.sh

## If the package won't let you "Show Package Content" on right-click then...
pkgutil --expand Foo.pkg some/path

## This will probably yield one more more child .pkg files.  Inside them
## look for the Payload file.  Then...
mv Payload Payload.gz
gunzip Payload.gz

## Which results in Payload uncompressed.  Use 'cpio' to extract files...
cpio -iv < Payload