Simple too to monitor one or more urls. The tool will beep in error events.
npm install -g monitor-url-tool
monurl 5000 http://www.example.com
will check example.com every 5 seconds.
monurl 5000 servers.conf
while servers.conf will look like this:
google, http://www.google.com
yahoo, http://www.yahoo.com
#comments can be embedded in the file, but only in their own line
facebook, http://www.facebook.com
the tool also provides a cli which allows adding servers in runtime:
monitor> addServer('beer', 'http://beer.com')