What is the Apple / OS X name for "Alternate Data Streams"?

Solution 1:

Apple uses "multiple fork" or the shortened form "multi-fork" consistently through its documentation, so it seems it is the official term. I list here a few examples:

https://developer.apple.com/library/mac/#documentation/General/Conceptual/SLGlobalGlossary/Glossary/Glossary.html (Last updated: 2010-07-09)

HFS+ Hierarchical File System Plus. The Mac OS Extended file-system format. This format adds support for filenames longer than 31 characters, Unicode representation of file and directory names, and efficient operation on very large disks. HFS+ is a multiple-fork volume format.

https://developer.apple.com/library/mac/#documentation/Porting/Conceptual/PortingUnix/io_porting/io_porting.html (Last updated: 2012-06-11)

(...) some Mac applications also take advantage of the HFS+ file system’s ability to handle multi-forked files.

https://developer.apple.com/library/ios/#documentation/CoreFoundation/Conceptual/CFBundles/AboutBundles/AboutBundles.html (Last updated: 2010-07-08)

Bundles can reside on volumes of many different formats, including multiple fork formats like HFS, HFS+, and AFP, and single-fork formats like UFS, SMB, and NFS.

When talking about "fork" in computing I can only think of either HFS+/HFS forks or the system call for creating a child process.

Solution 2:

I've just become interested in this topic again and started poking around.

This time I've noticed that the term "named fork" is widely used for forks other than the data fork and resource fork.

Here are some references:

• Archive of old Apple developer docs "Using Pathnames"
• Mirror of old Apple developer docs "Reading, Writing, and Closing Files"
• Depreceated Apple developer docs "Creating and Deleting Named Forks"