MariaDB is the open-source successor to MySQL#
Documentation on the plain MariaDB image (the MariaDB-Drupal image is built on this).
Redis is a fast, open-source, in-memory key-value data store for use as a database, cache, message broker, and queue#
Solr is an open-source search platform#
Documentation on the plain Solr image (the Solr-Drupal image is built on this).
Varnish is a powerful, open-source HTTP engine and reverse HTTP proxy that helps to speed up your website#
Documentation on the plain Varnish image (the Varnish-Drupal image is built on this).