Suricata is an Intrusion Detection and Prevention (IDS/IPS) engine developed by the Open Information Security Foundation and its supporting vendors. The engine is multi-threaded and has native IPv6 support, file extraction capabilities, and many more features. It's capable of loading existing Snort rules and signatures, and supports many frontends through Barnyard2.
redBorder IPS is a high performance intrusion prevention system based on Snort running on top of a clustered pf_ring with specific enhancements. A Web management interface is provided to control a large number of such devices, including snort and device configuration, rule management, SNMP monitoring, user roles, and multi-domain support.