VisualVM is an All-in-One Java Troubleshooting Tool
Enterprise-class, distributed monitoring solution for networks & apps
Database monitoring agent for zabbix
Pinger alert, STATICTICAL TABLES, send EMAILs or SMS by SMS GATEWAY
Open Source Managed File Transfer
Monitoring of websites with spider and email notifications
Web based application to easily monitor your organization performance
BGPHist stores MP-BGP updates activity and history into a database.
AlertOnFailure was inspired by XYmon, a Big Brother Compatible Monitor