The Open Source Network Management System

Zenoss is an IT infrastructure monitoring product that allows you to
monitor your entire infrastructure within a single, integrated
software application.

Key features include:
  * Monitors the entire stack
    o networks, servers, applications, services, power, environment, etc...
  * Monitors across all perspectives
    o discovery, configuration, availability, performance, events, alerts, etc.
  * Affordable and easy to use
    o unlike the big suites offered by IBM, HP, BMC, CA, etc...
    o unlike first generation open source tools...
  * Complete open source package
    o complete solution available as free, open source software