Great little article on how to make sense of the varnishstat output.
Useful pointers on how to store varnish cache on disk. Very easy, recommends using ext2 and noatime / nodiratime to improve disk throughput. Smart.
A magento varnish plugin that enables varnish caching on Magento sites.
Very interesting question that has lots of useful links on persistent object / value stores that are similar to memcache. Answer seems to be couchbase.
This says it all, couchbase includes memcached as part of it, and can operate in "pure memcache" mode or can add persistence and other features behind memcached. Sounds like it'll do what we're after.
Very useful article outlining the broad basics of optimising Magento. Includes links to more detailed information and lots of config file examples. Very useful.
Very detailed article explaining how Magento implements its caching mechanism. It seems to be some custom classes layered on top of Zend's caching framework. Useful read.
Varnish is a state-of-the-art, high-performance HTTP accelerator (reverse proxy). Varnish is designed by a BSD kernel developer to make full use of BSD / Linux kernel's ability to manage memory. It is extremely fast, up to 10 - 20 times faster than squid.
memcached is a high-performance, distributed memory object caching system, generic in nature, but intended for use in speeding up dynamic web applications by alleviating database load.
The WordPress WP-Cache2 caching plugin / platform. The plugin caches WordPress to static files and then serves those files instead of rebuilding the pages on every request.