I was today taking a look into several load-balancers for a project of a colleague.  I was especially interested in simple http load-balancers which would be easy to hack or easily remotely controllable. After searching freshmeat and for simple load-balancers in java and python in google. I turned up the following:

Pen allows remote configuration via telnet and seems to be well suited for our project. I still have to check how it handles connections and slots - can we emulate some kind of queue with it. It produces very nice statistics sending -USR1 signal to it.

One of our students (Mikhail Kasatkin) working on a load-balancer project pointed me to the following resources (I have to admit that I am not a great friend of Apache webserver, but this is a matter of taste):