A controller for caching large objects in unix shared memory.
This can be used for storing large constant objects, such as the theme cache or other large drupal arrays. Although this specific instance requires modification to drupal core, the performance can greatly improve over other caching methods such as memcache, when the objects are large and network latency becomes an issue. This does use memory on your web server that will not be released until rebooted or manually removed with the ipcrm command, so use it sparingly on items that are real performance issues.
This requires the php shmop extension.