Pound is the preferred load balancer because it is focused on just one goal, and that is directing inbound traffic to groups of computers that share a computational load.

Network utility that summarizes TCP/IP data sorted by host computer and protocol to monitor which hosts are using the most bandwidth.

Varnish provides a reverse proxy cache and has been an invaluable tool to put in front of dynamic image processing servers so that large groups of images can be resized and watermarked on the fly.