HAproxy is a high-performance and highly-robust TCP/HTTP load balancer which 
provides cookie-based persistence, automatic failover, header insertion, 
deletion, modification on the fly, advanced logging contents to help trouble- 
shooting buggy applications and/or networks, and a few other features. It uses 
its own state machine to achieve up to ten thousands hits per second on modern 
hardware, even with thousands simultaneous connections.

WWW: http://haproxy.1wt.eu/