Apple added support for extended attributes to HFS+ in Mac OS X 10.4 Tiger: http://arstechnica.com/apple/2005/04/macosx-10-4/7/#extended-attributes http://arst

Apple added support for extended attributes to HFS+ in Mac OS X 10.4 Tiger: http://arstechnica.com/apple/2005/04/macosx-10-4/7/#extended-attributes http://arstechnica.com/apple/2005/04/macosx-10-4/7/#extended... Today, resource forks are actually exposed through the extended attributes interface: http://arstechnica.com/apple/2013/10/os-x-10-9/9/#tags-implementation http://arstechnica.com/apple/2013/10/os-x-10-9/9/#tags-imple... You can see the source code for all this in Apple's Darwin open source repository. Example: http://opensource.apple.com/source/xnu/xnu-2782.40.9/bsd/hfs/hfs_xattr.c http://opensource.apple.com/source/xnu/xnu-2782.40.9/bsd/hfs... Please read this, written by the creator of resource forks, to learn why they exist: http://www.folklore.org/StoryView.py?story=The_Grand_Unified_Model.txt http://www.folklore.org/StoryView.py?story=The_Grand_Unified...