SkipoleMonitor is available at

Version 0.2 now released, this version adds the option to automatically send
email alerts should the status of any monitored host change.

What is SkipoleMonitor?

SkipoleMonitor is a free network monitor for Windows and Linux. On running
the program, a GUI window appears, and hosts can be added, which Skipole
Monitor will regularly ping, showing the results via a built-in Web server.
Hosts can be grouped, so the Web server will show group symbols that the
viewer can open to inspect the hosts, or further sub-groups, within.

License : GPL