Hyperic HQ manages more data center technologies out of the box than any other enterprise monitoring software. Recent additions include Vyatta routing software, Zimbra Collaboration Suite, (patches are for...) qmail, OpenLDAP, and a few others.
Now comes 2 more plugins: Alfresco and Sendmail. If you're an HQ admin, now you can easily add monitoring for both apps.
You can always find the latest HQ plugin info on the HyperFORGE: http://www.hyperic.com/hyperforge