Zabbix - Track, record, alert and visualize performance and availability of IT resources
SevOne - SevOne provides network managers with monitoring, troubleshooting, and performance reporting capabilities.
Centreon - Centreon is a network, system, applicative supervision and monitoring tool.
Flowmon - Clever Network Monitoring and Security Solution based on NetFlow, IPFIX and Network Behavior Analysis
Easy-IP - IPAM and DNS for Telecoms
Obkio - Simple Network Monitoring and Network Troubleshooting software to empower users to identify and troubleshoot network & application slowdown from the end-user perspective.