hfs-tool is a command line program that I wrote back in 1994 for reading HFS format (Apple) disks on Unix and MS-DOS systems.
Much like my nenscript program, I lost contact with the code after several years as email addresses changed. Eventually the program became surpassed by native implementations of the HFS filesystem on various platforms.
The code is still provided as part of the FreeBSD 9.2. See this URL for further information