The document discusses Cassandra and how it is used by various companies for applications requiring scalability, high performance, and reliability. It summarizes Cassandra's capabilities and how companies like Netflix, Backupify, Ooyala, and Formspring have used Cassandra to handle large and increasing amounts of data and queries in a scalable and cost-effective manner. The document also describes DataStax's commercial offerings around Apache Cassandra including support, tools, and services.