Are there any open-source graph-databases around which are able to store binary data, scale horizontally and optionally provide versioning of stored data?
I am overwhelmed by the sheer amount of dbs out there, but none of them seems to have all the desired features.
The binary storage, horizontal scale, and versioning requirements all sound like good candidates for a BigTable model like Cassandra or HBase. If you really need a graph database, those may not be a good fit, however. If you can expand a bit more on what the requirements are, we could make a better suggestion.