Currently (2023-01-03) em-4.0.15-lt.tar.gz is available at
	https://cdn.kernel.org/pub/linux/kernel/uemacs/
	with a matching sha256 sum.

May live at:

https://git.kernel.org/pub/scm/editors/uemacs/uemacs.git
(has changes as recent as 2018)

The README file there (tree hash 1cdcf9df88144049750116e36fe20c8c39fa2517)
matches em-4.0.15-lt.readme when whitespace is ignored.