Open Source Monitoring System for performance and availability.
Nagios network monitoring software is enterprise server monitoring
VoIP SIP and SKINNY quality analyzer and packet / audio recording tool
free netflow analyzer
Firewall log analyzer
Monitoring and reporting web gui for Bacula
Enhanced Apache Server Status page - for one or multiple servers
Painel de Monitoramento em PHP/MySQL
Fritz!Box SmartHome Monitoring with PRTG and AHA-Interface
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
inventory, asset management network monitoring and backup appliance
Webinterface to (un)ban IPs in Fail2Ban
PotHead
Open Source SIEM
Open source tool to monitor your servers and websites
Netflow visualisation and investigation tool