This chapter will offer an in depth look at what memcache is, and how it improves both website performance and scalability. It will look at how memcache achieves its performance, reviewing the difference between hash tables and databases, and explaining how memcache can help websites of all sizes. This chapter will explore Drupal's contributed memcache integration module, and the patches that come with the project. It will look at how to modify Drupal so anonymous pages can be served directly out of RAM, and so pages for logged-in users can be assembled from objects stored in RAM. Finally, it will look at the areas in Drupal that most benefit from memcached integration.