Autopkg is a project born out of the need to automate one of the more tedious tasks that face Mac Admins: figuring out when a piece of software has been updated, downloading it, and doing whatever it takes to make that software 'live' in your distribution or management system of choice. Munki was designed more recently than some other software distribution systems, and started out with the concept of 'tracks' or phases a piece of software will go through before it is offered to all of the clients participating in the system. Autopkg can integrate with it by simply copying the downloaded package into the repo, among other actions that have the potential of offering the software to clients immediately.
The JAMF Casper suite has many similar features, but as it was built under different circumstances it has other considerations and steps one would use when approaching the same set of tasks. Autopkg does not consider one software distribution system more special than another, and presents an open framework for f