Mac
The Mac (short for Macintosh) is a family of personal computers made by Apple. The Mac line began in 1984 and continues to the present day, but the brand names, processors, operating systems and development tools used on Macs have changed significantly over time.
macOS (previously called Mac OS X) is a Unix-based operating system that has been preloaded on Macs from 2001 to today. Mac OS (previously simply called System Software) was the operating system preloaded on Macs from 1984 to 2001; it is retroactively referred to as classic Mac OS to avoid confusion with the current macOS.
NetHack has been available for classic Mac OS since at least NetHack 3.0.5, released in 1989. It continued to be supported during the long reign of NetHack 3.4.3, but it is unknown if NetHack 3.6.0 or later will build or run on it.[1] In the NetHack source code, files relevant to classic MacOS are stored in sys/mac.
NetHack is currently supported for modern macOS. Since macOS is a Unix-based system, the build files are in sys/unix, not in sys/mac. It can be compiled with tiles, according to this discussion.
