ReMon - is a remote process monitoring and control solution originally developed as an in house tool to monitor multiple tomcat instances it evolved into a complete product. it's written from scratch in Python and uses push client/network concept.
Spike Asset Manager (SAM) is an open-source cross-platform framework for probing a system for components and reporting them. It includes a driver file that probes for components commonly found in a LAMPJ stack (Apache, MySQL, PHP, Tomcat, etc).