MacMiNT is a port of the MiNT kernel written for the Atari ST. It provided a multitasking UNIX-like environment. Unlike MiNT, MacMiNT lacks support for both TCP/IP and the X Window System. However, it still provides a multitasking environment for using programs like tcsh, gcc, emacs, and more.
How to Install?
It's simple. Just expand the archive into wherever you like.
Caution: Some versions of StuffIt Expander incorrectly converts end-of-line code of text files from LF to CR. In that case, MacMiNT aborts with "exit code: -39". If it happens, delete the expanded files, change StuffIt Expander's cross platform preference to "Never", and expand again.
Usage
Double click "jet" to start MacMiNT. Console window appears, and the login shell (tcsh, by default) runs in it, without login prompt.
To quit MacMiNT, exit from the login shell by pressing control + D or typing "exit".
Although "File" menu has "Quit" command, it should be considered as emergency purpose.
Don't move, change name, or touch the contents of mint folder while MacMiNT is running, or a bad thing may occur...
Takanori, Hoshi. (2000). Hoshi's New MacMiNT Page. www.sra.co.jp/people/hoshi/macmint/index-e.html
(7.62 MiB / 7.99 MB)
System 7.0 - 7.6 - Mac OS 9 / DiskCopy image, compressed w/ Stuffit

30 /

2015-07-24 /

89e6be852f39bc31649ff44ce4e1593944deb452 /

/
(5.86 MiB / 6.14 MB)
System 7.0 - 7.6 - Mac OS 9 / compressed w/ Stuffit

21 /

2014-04-14 /

103eb10bcbeba52655deb12142c8ba4f90dab9a1 /

/
Architecture 

IBM PowerPC
Compatibility notes 
- Turn off Virtual Memory.
- It has been reported to run on Mac OS 7.6 through 9.0.
Emulating this? It could probably run under:
SheepShaver