Sourcefire's Intrusion Sensor 2000 (IS2000) is an Intel-based appliance that runs a hardened version of Linux and the intrusion detection software. It uses two Fast Ethernet interfaces and has a throughput of 100Mbps.
Sourcefire calls its 3D System a "network defense system," avoiding the now loaded terms IDS and IPS. But while some of its components are strictly IDS or IPS, the package as a whole deserves a much broader description.