GLPI - GLPI is the Information Resource-Manager with an additional Administration- Interface.
TrafficMonitor - TrafficMonitor is a network monitoring suspension window software in Windows.
Lansweeper - Lansweeper discovers Windows, Linux and Mac machines in your network.
NetBalancer - NetBalancer is a Windows application for local network traffic control and monitoring.
FusionInventory - Fork of the OCS Inventory project that enables users to inventory their IT assets.
FreeMeter - Monitor network bandwidth (C#.NET 2k/XP+). Desktop and Systray graph.