IP Monitor notifies you when your public IP address changes
Storage, SAN, LAN Performance Monitoring: IBM,NetApp,Hitachi,HPE,EMC
Scalable, distributed monitoring system for high-performance computing
Intelligently block brute-force attacks by aggregating system logs
Full-Stack Infrastructure Performance Monitoring
Daemonlogger is a packet logger and soft tap developed by Martin Roes
netflow collecting and processing tools
Vendor-neutral programmable observability pipelines
Light-weight system monitor for X
ICMP-based network bandwidth measurement tool
FAN is Linux-based operating system provided Nagios
Zenoss - Intelligent IT Operations Management
Enhanced Apache Server Status page - for one or multiple servers
Graphical network connections viewer for Linux
Free and Open Source network access control (NAC) solution