Nagios Open Source network monitoring software - The Standard In ITM
Open Source Monitoring System for performance and availability.
Application Performance Monitoring System
VoIP SIP and SKINNY quality analyzer and packet / audio recording tool
Enhanced Apache Server Status page - for one or multiple servers
Monitoring and reporting web gui for Bacula
Firewall log analyzer
Produces a graphical map of hosts, switches and routers in a network.
Stream manager
Enterprise-class, distributed monitoring solution for networks & apps
Xplico is a Network Forensic Analysis Tool (NFAT)
PHP-based looking glass for Cisco, Juniper & Zebra/Quagga routers
OPTOSS Next Gen Network Management System (NG-NetMS)
REST interface and configuration GUI for Nagios
PotHead
Open source tool to monitor your servers and websites
Open Source SIEM
Netflow visualisation and investigation tool
DOCSIS network management