MFS
From Just Solve the File Format Problem
MFS (Macintosh File System) was the filesystem used on early Apple Macintosh computers for file storage on Apple double-density 3 1/2" disks. It was soon replaced with HFS (Hierarchical File System).
MFS stored files in a single flat structure without subdirectories; the illusion of "folders" was created by including a "directory handle" in each file entry so that the single directory could be scanned to find files that belong to a particular virtual folder. File names could be up to 255 characters, though Finder didn't support more than 63 or 31 characters (depending on the version). Resource Forks were introduced in MFS.
A MacFUSE implementation of MFS that seems to work is available at [1] (SVN: [2] ).
