Zabbix

Zabbix is an opensource enterprise networks and applications monitoring solution. High performance real time monitoring means that tens of thousands of Servers, Virtual Machines and Network devices can be monitored simultaneously. Along with storing the data, visualizations features are available ( overview, maps, graphs, screens, etc.) as well as very flexible way of analyzing the data for the purpose of alerting.

For storing data Zabbix uses MySQL, PostgreSQL, SQLite, Oracle or IBM DB2.

Zabbix is released under the terms of GNU General Public Licence version 2.

Features:

• Zabbix comes with web based interface, secure user authentication and a flexible user permission schema.
• Polling and trapping is supported.
• Web monitoring.
• JMX monitoring.
• Monitoring of WMware virtual machines.
• Automatically discover network servers and devices.
• low level discovery.
• Centralized monitoring system.
• Highly efficient Zabbix agents for UNIX and Windows.
• Web based interface.
• SLA and ITIL KPI metrics on reporting.
• Flexible e-mail notification on predefined events.

For download click here.

OpenNMS

OpenNMS is a free an open source enterprise grade network monitoring and network management platform. Released under the GNU general public licence, version 3.

The goal is for OpenNMS to be truly distributed, scalable management application platform for all aspects of the FCAPS network management model while remaining 100% free and open source. Currently the focus is on Fault and Performance Management. 

Platform Support: OpenNMS is written in Java and thus can run on any platform with support for a Java SDK version 1.6 or higher. Pre-compiled binaries are available for most Linux distributions, Windows, Solaris, and OS X.

Features:

1. Core features 
   
   
2. Event management
3. Notification features
4. Integration features 
5. Reporting Features
6. Trouble Ticketing/ Help Desk Plugins
7. User Interface Features

You can check the Demo.
Tutorials and Installation.