Flexera - Secunia CSI is an agent service on Windows computers that helps you identify the software and keep it up.
Zabbix - Track, record, alert and visualize performance and availability of IT resources
Mugato - Automatic insights on your IT-infrastructure.
Datadog - See metrics from all of your apps, tools & services in one place with Datadog's cloud monitoring as a service solution. Try it for free.
Device42 - Automatically maintain an up-to-date inventory of your physical, virtual, and cloud servers and containers, network components, software/services/applications, and their inter-relationships and inter-dependencies.
Wireshark - Wireshark is a network protocol analyzer for Unix and Windows. It lets you capture and interactively browse the traffic running on a computer network.