Comparison of File and Directory Name and File Systems on Macintosh, PC and Unix Computers and Operating systems.

Mac OS file names compatibility:
• Mac OS9 supports HFS and HFS+ File system and may be up to 31 characters long. Max OSX supports HFS+ and UFS (Unix File System) and may be up to 255 characters long.
• Colon ":" is used as a directory separator.
• File and folder names may use any characters except colon ":" and forward slash "/" which is used for directory separators on OS9 and OSX.
• Filenames preserves case but are not case sensitive.

Windows file names compatibility:
• Windows uses two different file systems: the File Allocation Table (FAT) file system and New Technology File System (NTFS).
• File and folder names may be up to 255 characters long on FAT file systems and 256 characters long on NTFS. Full pathnames may be up to 260 characters long.
• There is a limit to the full pathnames of 260 characters long.
• Backslash "\" is used as the directory separator.
• File and directory names may not contain the special characters: "/\*?<>|:
Periods are allowed in file and directory names, but not as the last character. for example "letter.doc" is legal but "letterdoc." is illegal file name.
• Filenames preserves case but are not case sensitive.

UNIX file names compatibility:
• Unix base operating systems mostly use the UFS (Unix File System).
• File and folder names may be up to 255 characters long.
• Forward slash"/" is used as the directory separator.
• File and directory names may not contain the special characters: space and /
• Filenames preserves case and are case sensitive.