The Active Monitoring System
Monitorix is a free, open source, lightweight system monitoring tool
A network security analysis and monitoring toolkit Linux distribution.
Storage, SAN, LAN Performance Monitoring: IBM,NetApp,Hitachi,HPE,EMC
Main repository for munin master / node / plugins
Full-featured enterprise network management tool
FlowViewer is a web-based netflow data analysis tool.
This is now also available here github.com/sharkcz/collectl.git
Tools for Linux/Unix sysadmins
Monitorix is a system monitoring tool
OPTOSS Next Gen Network Management System (NG-NetMS)
Open Source SIEM
Netflow visualisation and investigation tool
Scalable, distributed monitoring system for high-performance computing
MitM pentesting opensource toolkit