PRTG is #10 in Top 10 IT Monitoring software

https://www.paessler.com/prtg

PRTG Network Monitor is an agentless network monitoring software. It can monitor and classify system conditions like bandwidth usage or uptime and collect statistics from miscellaneous hosts as switches, routers, servers and other devices and applications.

Positions in ratings

#10 in Top 10 IT Monitoring software

Alternatives

The best alternatives to PRTG are: Zabbix, SolarWinds, Nagios, Cacti, SpiceWorks, Splunk, ManageEngine