Quick story: every "server monitoring" tool I tried did the same thing show me a nice graph, then leave me to open a terminal anyway the moment something actually went wrong. CPU spike at 2am? Cool, now go SSH in, find the process, kill it, restart the service, hope it comes back clean. The monitoring part was never the hard part. The fixing part was.
So I built MonitorFree. It's live CPU/memory/disk/network metrics like you'd expect, plus file and listening-port change watchers, a correlated "what happened" timeline when an alert fires so you're not piecing together three different logs by hand, and SMART disk health checks that catch a failing drive before it takes the server down.