Zabbix open source data monitoring, graphing, messaging!

Zabbix is the ultimate open source availability and performance monitoring solution. Zabbix offers advanced monitoring, alerting, and visualization features today which are missing in other monitoring systems, even some of the best commercial ones. Below is a short list of features available in Zabbix:

auto-discovery of servers and network devices
low-level discovery
distributed monitoring with centralized web administration
support for both polling and trapping mechanisms
server software for Linux, Solaris, HP-UX, AIX, FreeBSD, OpenBSD, OS X
native high performance agents (client software for Linux, Solaris, HP-UX, AIX, FreeBSD, OpenBSD, OS X, Tru64/OSF1, Windows NT4.0, Windows 2000, Windows 2003, Windows XP, Windows Vista)
agent-less monitoring
secure user authentication
flexible user permissions
web-based interface
flexible e-mail notification of predefined events
high-level (business) view of monitored resources
audit log
Why Choose Zabbix
There are many reasons to choose Zabbix monitoring solution over its competitors. The best way to make sure it is the #1 choice for your organization is to give it a try. But if you have limited time, look at some of the arguments below:

an open source solution provides freedom with no "lock in" and security through the availability of source code. This includes not only Zabbix itself, but also components required (Linux, Apache, MySQL/PostgreSQL, PHP)
very easy setup and simple configuration process ensures low learning curve and therefore low cost of ownership
highly efficient agents for UNIX and Windows (x32, x64,Itanium) based platforms provide wider monitoring capabilities with greater speed
centralized monitoring system allows to store all information (configuration and performance data) in relational database for further easier processing and re-use of data
built-in rich visualization capabilities allow to work with your data faster and smarter
built-in housekeeping procedures allow to keep your data organized well