xemacs21-bin binary package in Ubuntu Mantic arm64

 XEmacs is a full fledged programming language with a mail reader,
 news reader, info browser, web browser, calendar, specialized editor
 for more programming languages and other formats than most people
 encounter in a lifetime, and much more.
 .
 After starting it up peruse the Help menu and read more on its
 origins and what it can do.
 .
 You will need one of xemacs21-mule, xemacs21-nomule, or
 xemacs21-mule-canna-wnn to actually run xemacs.

Source package