Everyone seems to like the Uptime server, and in that vein...
I thought I should point out
http://www.altara.org/mars.html
the Mars network services monitor. This is a Java based application
that lets you set up monitoring for one or more machines. It will
automatically email you when a monitored service is down.
It knows how to monitor ftp, http, ssh, imap, pop3, and smtp services.
You can configure when it checks (every so many seconds) and what it
does, as well as setting the timeout. I have found it very useful.
