From Raden Solutions:
NetXMS Management Console is an multi-platform open source network management and monitoring system. It provides comprehensive event management, performance monitoring, alerting, reporting and graphing for all layers of IT infrastructure from network devices to business application layer. The system has three-tier architecture: the information is collected by monitoring agents (either our own high-performance agents or SNMP agents) and delivered to monitoring server for processing and storing. Network administrator can access collected data using rich client application or web interface.