FreeMeter - Monitor network bandwidth (C#.NET 2k/XP+). Desktop and Systray graph.
NetBox - NetBox is an open source web application designed to help manage and document computer networks. NetBox was developed specifically to address the needs of network and infrastructure engineers.
Network Lights - Network Lights is a Windows program, which blinks keyboard LEDs (Light Emitting Diode) indicating outgoing and incoming network packets on network interface.
DCImanager - DCImanager is a platform for managing physical equipment. Connect any physical equipment to a single platform. Use the platform to manage your servers, switches, PDU as well as physical and virtual networks.
TrafficMonitor - TrafficMonitor is a network monitoring suspension window software in Windows.
Opendcim - a free, web based Data Center Infrastructure Management application.