Light-weight system monitor for X
Disk Inspection and Monitoring
Monitorix is a system monitoring tool
Pinger alert, STATICTICAL TABLES, send EMAILs or SMS by SMS GATEWAY
track log files, block intrusions, and much more
Urban Terror Server Monitoring Program
Monitoring backup jobs tool for Symantec NetBackup
NDPMon - Neighbor Discovery Protocol Monitor
Fast Track Systems Monitor (FTMON) is an open source monitoring engine