I haven’t followed WWDC 2019 beyond the long-awaited Mac Pro announcement, but I’m stoked for this news.

  • zsh is a far better interactive shell than bash. It’s more extensible, its auto-complete is faster, autopushd is wonderful, and from my selfish perspective it closer matches ksh, my current shell family of choice.

  • It’s MIT/BSD-ish licenced. I prefer this to the GPL for reasons that are beyond the scope of this post, but clearly so does Apple based on their development and support for llvm and Darwin’s BSD userland.

  • For scripts, people should be writing Bourne-shell code anyway. I know I’m fighting a losing battle here, but portability and correctness are important.

  • bash may be a pun, but it sounds aggressive. Pronouncing zsh sounds like a hipster fruit juice.

bash fans may be disappointed or frustrated by the decision. But to them I repeat their advice given simultaneously nicely, and condescendingly, when 10.4 Tiger replaced tcsh: you’ll still be able to run it, and you can always swap it back if you want.