actually both in many cases, Neo4j does have quite a hostile license, but its biggest downside is that it is graph only, whereas OrientDB (and ArangoDB which is

actually both in many cases, Neo4j does have quite a hostile license, but its biggest downside is that it is graph only, whereas OrientDB (and ArangoDB which is also worth looking at) are "multi-model" - you can use them as pure document (or even key / value) stores, and the graph is just another way of viewing / representing that data. This is really powerful and means that you don't have the problem of duplicating data between different database systems or needing to do cross-data-store joins in your application.