Xplico is a Network Forensic Analysis Tool (NFAT)
REST interface and configuration GUI for Nagios
PotHead
Open source tool to monitor your servers and websites
Scalable, distributed monitoring system for high-performance computing
A simple cacti viewer for smartphones
Weblooker monitors serveral services on multiple systems for their sta
Detect Flooder IPs, Reduce Attack Surface against HTTP Flood Attacks
A flexible, extendable content filter