An eye on your system
Enhanced Apache Server Status page - for one or multiple servers
FlowViewer is a web-based netflow data analysis tool.
Xymon monitors your hosts, your network services, and everything else.
Zenoss - Intelligent IT Operations Management
Show devices in a lan
Pinger alert, STATICTICAL TABLES, send EMAILs or SMS by SMS GATEWAY
track log files, block intrusions, and much more
Track your ARP/MAC table changes and so much more
Open Source SIEM
Open source tool to monitor your servers and websites
Brute-forcing WAN/LAN services
Scalable, distributed monitoring system for high-performance computing