MacBinary is a format for encoding Macintosh files for transmission including directory metadata and both the data and resource forks, so that all system-specific aspects of the file can be reconstituted at the other end of the transmission. It is similar in concept to the Binary II format for the Apple II. Some other archiving and transfer programs had support for MacBinary built in, including a version of BinHex which uses this encoding (though there are other BinHex versions that have their own manner of including resource fork data).
Several different versions of this format have been released to accommodate changes in the Mac filesystem. (There was a MacBinary II, MacBinary III, and a proposed but little-used MacBinary II+.) Since the release of OS X, different archivers have been used and MacBinary has gone out of common use.
- MacBinary II spec
- MacBinary II+ proposed spec
- MacBinary Standard Proposal - Original version, revision 3 (from archive.org)
- MacBinary II Standard Proposal - Revision 7/24/87 (from archive.org)
- MacBinary III Standard Proposal (from archive.org)
- Collected MacBinary specs, from The Unarchiver GitHub wiki
- Macintosh Paint, from the Encyclopedia of Graphics File Formats - Includes a description of MacBinary
- MacBinary format description in the Apple Mac Sourcebook (1989)