BioNetDB is a storage engine and analysis framework for biology data based on Neo4j graph database. BioNetDB models biology data as a network of nodes and relations. Biology data comes from different formats and sources it comprises system biology data from Reactome, annotation data from CellBase and human genetic variations from healthcare centers' clinical data. As commented, BioNetDB relies on Neo4j that allows users to access biological data using the Cypher query language (similar to SQL in relational databases), in addition, Neo4j is highly optimized for queries and it is scalable and reliable.
BioNetDB is an open-source project and as such, we welcome everyone who wants to contribute in any way they can :) Helping with the development, documentation or testing and bug reporting are always useful! If you want to get involved in some way, please join our mailing list opencb@googlegroups.com.