Open Monitor is an Open Source network monitoring tool for the Windows operating system that enables you to monitor websites and networks
It comes with options to monitor multiple local and remote servers, and notification options that inform system administrators if services or programs are not accessible.
The main interface of the software is divided into a quick server check option at the bottom which can be used to check if services such as HTTP, FTP or POP are running on domains or IP addresses.
Open Monitor display the results in the same interface after the scan finishes automatically.
Probably more interesting than the quick check function is the option to add servers permanently to the monitoring tool so that they are scanned regularly by the application.
You need to enter a server name which is used for identification, and a server address which is usually the IP address or hostname of the server.
A list of services are selected and will be scanned unless unchecked by the user.This includes HTTP, FTP, POP and Telnet among others. You may change ports of services right there in the program interface.
Alerts can be enabled or disabled in the same interface as well. These do have to be configured separately though and can inform the user by email, screen message, or sound, and you may also run a program on an alert on top of this.
There is also the possibility to add http url checks in addition to the default port scans that Open Monitor runs. This allows you to specify URLs, ports, alerts and words that a page should include or not include.
This can be used for example to verify that a page is up by checking for a word on that page that is always there. Can also be used to run scripts that output a simple message in the end, e.g. a database check that is displaying ok if the database is up and running.
Open Monitor is a straightforward, easy to use, network monitoring software that can monitor popular services. Alternative programs are the server monitoring software IT Service View, Newt, the website monitoring software SiteMonitor or the Microsoft Network Monitor.
Update: Please note that Open Monitor has last been updated in 2004. I was not able to test the application on newer versions of Windows as I'm running a 64-bit version which the program is not compatible with. While it may still run on 32-bit versions of Windows, it is highly suggested to use a different program that is updated regularly.