Thought HN might like this. Sendmail was one of the most &#x27;non-Unixlike&#x27; Unix apps: a big monolith that included UUCP, X400, and other non-SMTP support whether you wanted it to or not. It frequently needed patching - IIRC the Morris worm used it to break into systems. It used a non-human readable config format, so everyone had to use another similarly awful macro language to edit it. It was awful, but everyone doing SysAdmin in the early 2000s had to learn it because it was <i>everywhere</i>.<p>Now it&#x27;s mostly gone. Hooray.