[ Thanks to Aditya Patawari for this link. ]
Wackamole is an application which manages a bunch of IPs which
should be accessible from outside all the time. Given a set of
machines and a IPs, wackamole will ensure that if any machine goes
down, other machine will take up its IP almost instantly and
outside world will see no impact. It tries to balance the number of
IPs across the number of machines available. Wackamole uses Spread
network messaging system.