This site is monitored with Zenoss Core.
System monitoring tools have been around since the beginning of systems. A quick Google search for “system monitoring software” returns over 21 million results. It’s literally from “A” to “Z”. Accel Ops to Zenoss with a ton of systems in between. Each has its own hook, some with reporting for the bosses and some application specific. All can measure uptime. Picking one is like choosing ice cream, what flavor do you like?