Is there any good software for monitoring the health of a collection of related software?

Requirements are as follows:

• Web-based, deployable on standard Linux/BSD software.
• Configurable to support a variety of processes, scheduled at various intervals.
• Some sort of dashboard interface, for monitoring status, viewing errors, etc.

As an example, suppose we have a daily export that's scheduled to run at 6AM each morning. After the export completes, it would POST a status message, saying it had completed, passing in some sort of application key to identify the export. If that status message hadn't come in, by, say, 6:30AM, an e-mail might be sent, that application should go red on the dashboard, etc.

Applications should also be able to post error/warning messages.

Basically the goal is to be able to monitor all of our internal projects from one system, rather than a multitude of e-mails, log files, etc.

I suspect that I'll probably have to end up writing this from scratch, but I just thought I'd ask.