vded is a simple REST-type method for tracking deltas of ever-increasing values (although it handles resets, etc., pretty well). It is meant to accept submissions of values which increment, then determine the delta between that value and its predecessor, as well as figure the rate over time.
Patchman is a patch status monitoring tool for Linux systems. Patchman clients send a list of installed packages and enabled repositories to the server. The server (CLI or Web) tells the user which hosts require updates, whether those updates are normal or security updates, and shows installed packages that are not part of any repository. Hosts, packages, repositories. and operating systems can be filtered using features or arbitrary tags. For example, you can find out which hosts have a certain version of a package installed, and which repository it comes from. Patchman does not (yet) have the ability to update packages on hosts.
Shinken is an advanced monitoring system that is based on Nagios, but redesigned and rewritten from scratch while maintaining compatibility. It can monitor all IT devices from systems to end user applications. In case of a failure, Shinken can alert the operation engineers so they can promptly repair it. It has the same capabilities as Nagios along with more advanced built-in facilities such as load balanced and high availability monitoring.