Varnish is a HTTP accelerator, build from ground up with performance in mind. Varnish is targeted primarily at the FreeBSD 6/7 and Linux 2.6 platforms, and will take full advantage of the virtual memory system and advanced I/O features offered
WordPress.com use Amazon S3 for storing images, they do not serve images directly from Amazon, they use Varnish reverse proxy at front end, so not all images need to be served from S3, Varnish cache popular images and serve directly
Today i was reading a lot on how to web server scalability, mostly due to my lighttpd web server is above load level 1 most of the time. I found an interesting video that talks about youtube server setup and
