Now that the WWDC keynote is over, Apple has published the names of the developer sessions to attendees at the conference. Previously masked by placeholder names, there are a bunch of events that folks can now plan on attending—including, apparently, a session discussing Apple's new file system for macOS.

Dubbed APFS, for "Apple File System," the session description implies that the new file system is a replacement for the aged HFS+ file system, which has been used in one form or another by OS X since its launch back in 2001. We're pretty light on details at this point, but the session description says that APFS is designed from the ground up to be optimized for use on SSDs and other flash-based media, and that it was "engineered with encryption as a primary feature." The description also notes that the file system scales—from the desktop all the way down to watchOS.

We don't know if the new file system is Apple's own creation or if it's an adaptation from an existing journaled, encrypted file system. OS X (now macOS) power users have long had hopes that ZFS will take over as Apple's primary desktop file system—and, indeed, for a while it looked like that was going to happen. With the APFS introduction being made here at WWDC, however, it's very likely this is an Apple original.

Regardless of its pedigree, APFS is apparently quite good—at least according to one Ars alum. Shortly after the keynote, the venerable John Siracusa sent out the following tweet:

The new file system is real, and it's…spectacular? — John Siracusa (@siracusa) June 13, 2016

Color us intrigued. We'll be digging into APFS as soon as humanly possible.

Update: Keen-eyed readers have sent in links to the preliminary versions of the APFS documentation on Apple's developer site. We're reading right now!

Update again: The developer documentation is up, and we've got a longer analysis of APFS file system right here.