netifyd - The open source netifyd engine performs deep packet inspection and analysis on network traffic.
TrafficMonitor - TrafficMonitor is a network monitoring suspension window software in Windows.
libprotoident - Libprotoident is a library that performs application layer protocol identification for flows.
NetBalancer - NetBalancer is a Windows application for local network traffic control and monitoring.
L7 Filter - ClearFoundation is a developer community for ClearOS, a Linux Internet Network, Gateway and Server for small business and distributed networks.
FreeMeter - Monitor network bandwidth (C#.NET 2k/XP+). Desktop and Systray graph.