For users on MacOS, Chef maintains a Homebrew Cask that makes it easy to install and keep up-to-date ChefDK, Chef InSpec, and Chef Workstation.
brew cask install chef/chef/chefdk
# or
brew cask install chef/chef/inspec
# or
brew cask install chef/chef/chef-workstation
Packages can be easily upgraded after being installed via Homebrew
Upgrading one package:
brew cask upgrade chefdk
Upgrading all of your Casks:
brew cask upgrade