Server Monitoring Program
 

Does anyone know of a server monitoring program that I can install on a local machine (fedora core 4), to monitor my server that is off-site?

I want to be notified by e-mail if one or more of the following occurs:
- server is down
- apache is down
- webDNA server is down
- ftp server is down

I believe Mon is a suitable service. Simple ... does anyone have a link to a howto for Mon or any other suitable program?