Mavericks CAN mount APFS disks after all. Why?

Guy Burns wrote:

I had just assumed that Mavericks could not read APFS under any circumstances. But it turns out another iMac can do the translation. That's what was so surprising.

Mavericks is not reading an APFS file system if you are accessing the Mac through a network share. Mavericks is being presented with an SMB "interface" which is just presenting the files over SMB. The SMB sharing on the server is taking care of presenting the files across the network to your other Mac running Mavericks. It is just two Macs communicating using SMB. Only the Mac acting as the SMB server knows anything about the APFS file system and is presenting the information to connected systems in a different form.

APFS for Mac?

Since it is possible, is there software I can install that does the translation for me (instead of having to go via a network)? I did that sort of thing for NTFS a long time ago. I couldn't write to NTFS under Mavericks, so I bought NTFS for Mac from Paragon Software.

If someone did it for NTFS, did anyone do it for APFS? I might have a use for such a utility.

As @leroydouglas has mentioned...no. Even Paragon who usually has drivers available don't have any APFS drivers for macOS even though they do for Windows, Linux, and Android. That should be very telling. Mavericks is just too old and there would not be enough need for anyone to invest time & money into APFS support for it. Perhaps one day someone will write an open source driver for Mavericks, perhaps that will be you since you seem to have an interest in APFS support for Mavericks.

Anyone needing to share external drives between newer Macs and a Mavericks system should be using the HFS+ file system (aka MacOS Extended) for the external drive since both old & new Macs can read & write HFS+ drives. This option would be much safer than trusting a new third party driver for writing to an APFS volume.

If I understand your question correctly, you are able to read and write an Apple File System (APFS) formatted storage device provided that disk is connected to a Mac running macOS Mojave, and your Mac running Mavericks is in turn networked to that Mac over Wi-Fi. Is that correct?

Restated in that manner, the question sort of answers itself. When connected to a networked device, that device's file system or disk format doesn't matter. It could be HFS, NTFS, ExFAT, even RT-11 or CP/M... conceivably.

All that is correct. For example, when you download some file from the Internet (which is exactly what you do every time you load a web page, image, movie, music etc) the Mac you're using doesn't care about the server hosting that file. All it cares about is that it can establish that connection. That server might be running Linux, Windows, Solaris... doesn't matter. Nor does it matter what file system it uses. Nor in fact does it matter what Mac operating system you happen to be using when you download it.

Obviously, whatever you're using to load webpages doesn't even have to be a Mac. So you might as well say your Linux PC can read APFS — if the remote server hosting those files is running a macOS version recent enough to read APFS.

What file system does Apple use for all those programs on the App Store, or Music, or TV? I have no idea what they use today but in the past they used both AWS and Microsoft's Azure cloud storage services. Neither one would have used HFS or APFS. I believe Apple has long since moved everything in house, but even now I doubt they're using APFS. They certainly don't have to tell us.

APFS for Mac?

Doubtful... because whereas other file storage systems may be open source or publicly documented, APFS is proprietary and Apple has been completely un-forthcoming with anything but the most cursory details.