Brew 🍺

Allow alternate versions

brew tap homebrew/cask-versions

Casks

https://github.com/Homebrew/homebrew-cask-versions/tree/master/Casks

Custom

# Remote
brew install https://raw.githubusercontent.com/Homebrew/homebrew-core/86a44a0a552c673a05f11018459c9f5faae3becc/Formula/python@2.rb
# Local
brew install /opt/homebrew/Library/Taps/<user>/homebrew-python2/Formula/python@2.7.17.rb
brew install /usr/local/Homebrew/Library/Taps/<user>/homebrew-python2/Formula/python@2.7.17.rb