OrientDB is a Document-Graph NoSQL DBMS with the flexibility of the Document databases and the power to manage links of the Graph databases. Since one year ago OrientDB implements the TinkerPop Blueprints API. Blueprints are common API versus GraphDB used to build a lot of technologies like Pipes, Rexster and Gremlin. Gremlin in particular is a powerful scripting language to cross and manipulate trees and graphs.
OrientDB Graph Edition, called also "Graph(ed)", contains the last version of OrientDB and TinkerPop technologies in bundle and highly integrated. The product is Open Source and licensed as Apache 2 that means FREE for any kind of use.
For more information about download, installation and run look at: http://code.google.com/p/orient/wiki/GraphEdTutorial.
What is OrientDB?
OrientDB is a Document-Graph NoSQL DBMS with the flexibility of the Document databases and the power to manage links of the Graph databases. It can work in schema-less mode, schema-full or a mix of both. Supports advanced features such as ACID Transactions, Fast Indexes, Native and SQL queries. It imports and exports documents in JSON. Graphs of hundreads of linked documents can be retrieved all in memory in few milliseconds without executing costly JOIN such as the Relational DBMSs do.
OrientDB uses a new indexing algorithm called MVRB-Tree, derived from the Red-Black Tree and from the B+Tree with benefits of both: fast insertion and ultra fast lookup. The transactional engine can run in distributed systems supporting up to 9.223.372.036 Billions of records for the maximum capacity of 19.807.040.628.566.084 Terabytes of data distributed on multiple disks in multiple nodes.
OrientDB is FREE for any use because is released under the Apache 2 license.