I've been thinking about this for the past couple of days, and luckily I stumbled upon this discussion.
Having multiple FreeBSD servers running in VMs, I've been wanting for a unified monitoring interface (and perhaps combined with a syslog). My setup consists of ESXi hosting multiple VMs, which are mainly narrow-purpose FreeBSD servers or FreeBSD based distributions (FreeNAS, pfSense), and also the odd VM running Linux (Ubuntu) or Windows.
Which of these systems will, either out of the box or with simple add-on scripting, be sufficient to replace also the monitoring information received from the periodic daily/weekly e-mails?
Are there notable differences in interoperability/features (again, either out of the box or with add-ons) with FreeBSD based appliances such as FreeNAS and pfSense, and also non-FreeBSD systems such as various flavors of Linux, ESXi, and Windows?
And finally, do any of them, in your collective experience, have mobile friendly (and useful) versions of their interfaces (web/app)?