For some functionality, you will also need the following extensions:
-- memcache A client for the memcached server, which caches database
- information in volatile memory. This is important for
- adequate performance on high-traffic sites. You will
- also need a memcached server to store the data in.
+- opcache Improves performance a _lot_. Included in PHP, must be
+ enabled manually in php.ini for most distributions. Find
+ and set at least: opcache.enable=1
- mailparse Efficient parsing of email requires this extension.
Submission by email or SMS-over-email uses this.
- sphinx A client for the sphinx server, an alternative to MySQL