RuckZuck!

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.

Npackd (pronounced "unpacked") is an application store/package manager/marketplace for applications for Windows. It helps you to find and install software, keep your system up-to-date and uninstall it if no longer necessary.

Patch My PC is a small portable application that updates third party applications and Windows updates. It’s critical to keep software up to date to ensure vulnerabilities are patched. There are currently almost 100 third-party applications that Patch My PC can silently update, and the list is growing with each release!

Flexera Software Personal Software Inspector, previously Secunia PSI, is a FREE security tool designed to detect vulnerable and out-dated programs and plug-ins which expose your PC to attacks. Attacks exploiting vulnerable programs and plug-ins are rarely blocked by traditional anti-virus and are therefore increasingly "popular" among criminals.

A command-line installer for Windows.

Zero Install is a decentralised cross-distribution software installation system. Other features include full support for shared libraries, sharing between users, and integration with native platform package managers. It supports both binary and source packages, and works on Linux, Mac OS X, Unix and Windows systems. It is fully Open Source.

Kaspersky Software Updater is a Kaspersky Lab free utility that searches for updates for the applications installed on your computer.

OneGet is a unified interface to package management systems and aims to make Software Discovery, Installation and Inventory (SDII) work via a common set of cmdlets (and eventually a set of APIs). Regardless of the installation technology underneath, users can use these common cmdlets to install/uninstall packages, add/remove/query package repositories, and query a system for the software installed. Included in this CTP is a prototype implementation of a Chocolatey -compatible package manager that can install existing Chocolatey packages. »

win-get is an installer and software repository for Microsoft Windows, like apt-get in Linux.

A world of apps in the Microsoft Store.

WAPT is a package manager for Windows which provides installation, removal and upgrades of software in managed environment. Software can be deployed through a central management console. WAPT was modeled on GNU/Linux Debian APT, hence its name.

CoApp is an open-source package management system for Windows.