This is a pure-python TCP load balancer. It takes inbound TCP 
connections and connects them to one of a number of backend servers.

Features:
    * async i/o based, so much less overhead than fork/thread based 
      balancers. 
    * Multiple scheduling algorithms (random, round robin, leastconns, 
      leastconns+roundrobin)
    * If a server fails to answer, it's removed from the pool - the 
      client that failed to connect gets transparently failed over to a 
      new host.
    * xml based configuration file
    * separate management thread that periodically re-adds failed hosts 
      if they've come back up.
    * optional builtin webserver for admin (sample of the running 
      screen)
    * webserver has methods suitable for both interactive and automated 
      systems 

WWW: http://pythondirector.sourceforge.net/