Total Network Inventory: Professional PC audit and network inventory management software - fits best for a for companies of all sizes. Free for 60 days.
Network Inventory Advisor - Network Inventory Advisor audits all network software and hardware simply and efficiently
NetSpeedMonitor - NetSpeedMonitor is a lightweight Network Monitoring Toolbar for your Windows Taskbar
Lansweeper - Lansweeper discovers Windows, Linux and Mac machines in your network.
TrafficMonitor - TrafficMonitor is a network monitoring suspension window software in Windows.
Nmap - Nmap Free Security Scanner, Port Scanner, & Network Exploration Tool. Download open source software for Linux, Windows, UNIX, FreeBSD, etc.
GlassWire - Visualize network activity in detail, get notified when new apps access the network, look out for...