The original post has prose descriptions of each database but for my purposes a list of links is more than sufficient:
- ArangoDB
- Bitsy
- Blazegraph
- BrightstarDB
- Cayley
- Filament
- graphd
- GraphDB
- HyperGraphDB
- InfoGrid
- MapGraph
- Neo4j
- OhmDB
- OrientDB
- Orly
- sones
- Titan
- Trinity
- VelocityGraph
- Vertex
- Virtuoso
- Weaver
- WhiteDB
Like any other software, you should evaluate these graphs databases against your requirements and data. Do not assume that the terminology used in graph database documentation (such as it is) matches your understanding of graph terminology or indeed that used anywhere in published graph literature.
Having said that, some of the graph software listed above is truly extraordinary.