Appupdater provides advanced functionality to Windows, similar to apt-get or yum on Linux. It automates the process of installing and maintaining up to date versions of programs. It is fully customizable for use in a corporate environment.
NSDi (Network Services Discoverer) is a metarepository for big/small environments. This tool uses differents plugins to discover the services and software installed on servers.
You can create many repositories accesibles via API for many external tools.