munki is a set of tools that, used together with a webserver-based repository of packages and package metadata, can be used by OS X administrators to manage software installs (and in many cases removals) on OS X client machines.

munki can install software packaged in the Apple package format, and also supports Adobe CS3/CS4/CS5/CS6 Enterprise Deployment "packages", and drag-and-drop disk images as installer sources.

Additionally, munki can be configured to install Apple Software Updates, either from Apple's server, or yours.

munki is currently in use at organizations all over the world, managing software for thousands of Macs.

At Macworld SF 2011, Google’s Mac Operations and Security teams open-sourced Simian, a project that builds on munki, providing a highly-scalable server hosted on Google App Engine.

Check out the Wiki for some notes and documentation, and browse and/or check out the source. There's also an installer package in the Downloads section.

If you have questions, or need help getting started, the munki-dev group is the best place to start.