This is Dave Conroy's venerable/ubiquitous December 1985 version of microemacs/uemacs, with minimal updates to allow it to compile on Windows 7+, Linux, Cygwin and MSYS2.
To build, simply run make. It should compile on Linux or Windows.
Compiles to a 30k .exe on 64-bit Windows; 39k executable on 64-bit Linux.