[awalton]

> surely it would be extremely beneficial to have at least 1 open source filesystem that has good support across all platforms

The comedy of this is that there are actually plenty of FSes common to all three of these OSes, they're just not considered "modern"; FAT32 is still the most commonly used FS for interop, even as it shows its age with poor support for very large files (2+GB) and file systems, but you also have ISO(9660) and (the best answer we currently have) UDF supported by all three OSes natively and openly without patents or other licensing restrictions. The latter two are not commonly used as read/write filesystems, but have zero inherent restrictions on being able to be used in such a way.

However, the problem has been largely supplanted by having a fast and well-functioning network and people moving to "The Cloud" for, well, everything. It's hard to know how much of the Great Cloud Migration is caused by these kinds of intentionally engineered interoperability fails, especially the monumentally stupid exFAT patent... It's interesting to ponder given the people likely to complain the most about filesystems today are people who want to move large files (4+GB) between OSes without anguish, where the network is still just too slow to handle the task well.

[pmurT]

ISO 9660 is not at all a general purpose filesystem. Although fairly trivial to reason about and implement, little and big endian systems required entirely separate structures written to disc or files would not be accessible.

Myth 2 was a popular testing media in those days due to Apple and PC endian differences. As I recall Bungie did some clever crafting on the structures to share some of the media between platforms while keeping binaries separated. Even had a fun picture of soulblighter in Finder through icon trickery.

-wrote commercial CD mastering and storage software many many moons ago

[groby_b]

ISO9660 is many things.

However, it is not, not even close to, a decent file system. (And that's before we even get into RRIP and Joliet. /shudder)

And IIRC, ISO9660 has issues with being written - the path table needs to be ordered. Yes, you can make it modifiable on the fly, but the pain to do so is just not worth it.

[justabystander]

> UDF supported by all three OSes natively and openly

Wasn't there a major problem in that all the operating systems supported different versions of the UDF standard? And most of them treat it as an optical disk format, so I wouldn't be surprised if some of them acted like it was read-only.

[pjc50]

> It's hard to know how much of the Great Cloud Migration is caused by these kinds of intentionally engineered interoperability fails

+1. The great benefit of the "cloud" and the internet in general is as an escape from vertically integrated silos. Which is why all the big players are frantically trying to rebuild some kind of lock-in along different lines.

[poizan42]

How well does UDF perform for random-access read-write devices? It was my impression that it is optimized for read-often, write-rarely, possibly without possibility of overwriting.