Ben Nadel takes his previous HTML5 Cache Manifest experiment and converts it into an "App Mode" iPhone application that can fun in full-screen, offline mode.
Varnish is a state-of-the-art, high-performance HTTP accelerator. It uses the advanced features in Linux 2.6, FreeBSD 6/7 and Solaris 10 to achieve its high performance.
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.