From Raden Solutions:
NetXMS Server is an enterprise grade 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. It includes authentication with passwords, X.509 certificates, smart cards or RADIUS server, event correlation rules to reduce number of alerts and increase problem resolution speed, template-based data collection configuration for simplified management of large networks, and built-in interface with helpdesk system.