ModeShape 3 is an elastic, strongly-consistent hierarchical database that supports queries, full-text search, versioning, events, locking and use of schema-rich or schema-less constraints. It's perfect for storing files and hierarchically structured data that will be accessed by navigation or queries. You can choose where (if at all) you want ModeShape to enforce your schema, but your structure and schema can always evolve as your needs change. Sequencers make it easy to extract structure from stored files, and federation can bring into your database information from external systems. It's fast, sits on top of an Infinispan data grid, and open source. This presentation provides an introduction to how ModeShape 3 works.