OrientDB is an open source NoSQLdatabase management system written in Java. It is a multi-model database, supporting graph, document, key/value, and object models, but the relationships are managed as in graph databases with direct connections between records. It supports schema-less, schema-full and schema-mixed modes. It has a strong security profiling system based on users and roles and supports querying with Gremlin along with SQL extended for graph traversal. OrientDB uses a new indexing algorithm called MVRB-Tree, derived from the red–black tree and from the B+ tree.
The original author is Luca Garulli that started in 2010 by rewriting in Java the fast persistent layer of Orient ODBMS database, written in C++. In 2012 the project has been sponsored by Orient Technologies LTD company where the main author Luca Garulli is the CEO and founder.