Last week, I learned that David M. Tilbrook has died, which made me sad. I did not know him personally and cannot say much about his life, but I studied his publications and software ideas a lot, and consider them interesting, especially from a historic perspective. Unfortunately, most of these things are on websites taken down already, so this post will refer to pages on the Internet Archive extensively. [Update 2020-01-16: His son Joe Tilbrook sent me a mail stating that http://qef.com/ is up again.] I first came across David when I researched the history of the QED editor,