PortAuthority is described as 'provides a GUI for the MacPorts Unix software management system for Mac OS X. MacPorts is a powerful command-line tool for installing and updating a variety of Unix-based applications for the Mac'. There are four alternatives to PortAuthority for Mac, Windows, Xfce, Debian and Linux. The best alternative is Synaptic, which is both free and Open Source. Other great apps like PortAuthority are MacPorts (Free, Open Source), NeoSetup Updater (Freemium) and Pallet (Free, Open Source).
Synaptic is a graphical package management program for apt. It provides the same features as the apt-get command line utility with a GUI front-end based on Gtk+. * Install, remove, upgrade and downgrade single and multiple packages. * Upgrade your whole system.
The MacPorts Project is an open-source community initiative to design an easy-to-use system for compiling, installing, and upgrading either command-line, X11 or Aqua based open-source software on the Mac OS X operating system.
NeoSetup is a brand new concept of application installer and updater for Windows. It detects updates quickly and installs them at a click of a button. It will perform automated application installations from a collection of the most popular Windows programs.