Keryx is a portable, cross-platform package manager for APT-based (Ubuntu, Debian) systems. It provides a graphical interface for gathering updates, packages, and dependencies for offline computers. Keryx is free and open source
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.
Chocolatey is software management automation for Windows that wraps installers, executables, zips, and scripts into compiled packages. Chocolatey integrates w/SCCM, Puppet, Chef, etc. Chocolatey is trusted by businesses to manage software deployments.