HFS was introduced in System 2.1 ("System" being what we called "Mac OS" in the days before operating systems gained their broad and ubiquitous sex appeal). HFS improved upon the Macintosh File ...

If needed, Apple's TextEdit program can be used to modify hidden system files.

Finally, Amazon adds that its Elastic File System is fully compatible with Mac instances running macOS Big Sur on AWS.

Later VM versions, such as the ones for System 8 and System 9, have a server called The Outside World for moving files from the VM to your actual Mac desktop.