Homebrew is a package manager for macOS. It allows you to install various open source software.
It is really easy to use. Here is a quick summary:
/usr/bin/ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
Install a new application
brew install applicationName
Uninstall an application
brew uninstall applicationName
Display the list of installed applications
Display an application version
brew info applicationName
Update all the installed applications
You can also check the list of available packages on Braumeister.