This was written by Yusuke Endoh, who also wrote this submission to the IOCCC that I remember being arguably more astonished when I saw it for the first time: https://www.youtube.com/watch?v=QMYfkOtYYlg (ASCII fluid dynamics).
Wow, that was cool, never found that one when I went on a deep dive after discovering their quine relay. The other amazing ASCII program of theirs that I love is the Qlobe: http://mamememo.blogspot.com/2010/09/qlobe.html?m=1