OrientDB is an open source NoSQLdatabase management system written in Java. It is a document-based database, 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 SQL as a query language. OrientDB uses a new indexing algorithm called MVRB-Tree, derived from the Red-Black Tree and from the B+Tree; this reportedly has benefits of having both fast insertions and fast lookups.