Server monitoring from linux

Looking for program like servers alive, but for linux

[Tartan75]

I have been using Servers Alive on a windows PC to monitor my webservers. Im now replacing that PC with a computer running redhat 9, and looking for something linke servers alive, which will run on linux.

Essential features were:
check website is up (preferably check page includes certain content)
Issue alert to another computer if website is down

Any recomendations much appreciated

[Imaster]

I generally use InternetSeer Web Site Monitoring Service which Remotely monitors Web sites and provides alerts by email or pager email when sites becomes unavailable...

[internetseer.com...]

[Imaster]

Check this category as well:

[directory.google.com...]

[Tartan75]

Thanks for the suggestions. I should have also added that as its only a small number of sites i monitor, Servers Alive was free - which was a key attraction.

[bakedjake]

We use a combination of monitors. On an internal machine, we run nagios to monitor all of our mail/web/db/etc., and then we use Keynote to monitor a few transactional speed things, and network connectivity.

Keynote is expensive, but it's worth it, IMHO.