Homebrew!

Chocolatey NuGet is a Machine Package Manager, somewhat like apt-get, but built with Windows in mind. It is built on top of NuGet command line and the NuGet infrastructure.In terms of updates, it allows you to update nearly everything on your machine with a few simple keystrokes.

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+.

The Mac App Store is the best place to find apps for Mac. No more boxes, no more disks, no more time-consuming installation. Just like the App Store for iPhone and iPad, click once to download and install any app on your Mac.

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.

A command-line installer for Windows.

Nix is a powerful package manager for Linux and other Unix systems that makes package management reliable and reproducible. It provides atomic upgrades and rollbacks, side-by-side installation of multiple versions of a package, multi-user package management and easy setup of build environments.

What is Fink?

Cakebrew is the most convenient way to use Homebrew for your daily tasks! It does for Homebrew what Synaptics does to Linux package managers. From the Cakebrew UI, you can:

Rudix is a package-based, user-friendly way to extend the Unix portion of Mac OS X with additional network utilities, computer languages, development libraries, text tools and everything else you missed from command line.

Silent Install Helper determines the type of installation package and allows you to install programs in "silent" mode (without user intervention). Supported installers: Inno Setup, Smart Installer, Wise installer, NSIS, RAR \ ZIP \ 7z \ 7z Setup \ Free Arc \ Microsoft Cab SFX, Msi, Ghost Installer Wizard, InstallAware Wizard, InstallShield, Setup Factory Installer, Install4j Wizad, Driver Genius Installer, Actual Installer, the files .inf, .msu, and others. The app allows you to create CMD files, configuration files for Windows Post Install Wizard, displays information about the use of disk information, about the processes,also can use custom commands and scripts. Contains function of batch uninstall in "silent mode". »

Xara is a graphical interface for Ara; a utility for searching the Debian package database using boolean regexp queries.

The Silent Install Builder is a great tool if you need to quickly install a set of software on a multiple computers.

MacLibre is an Open Source Software Distribution for Mac OS X. It's simple, intuitive with applications you need. It brings a new way of software installation on your Mac. It installs a pack of great free/open source apps and keeps them updated for you.