Performance! I tested RDFox with the LUBM Benchmark and the timings recorded to load and query data were quite impressive.

I like the following features of RDFox: 1. server- datastore archtiecutre 2. multi-threading and sophisticated indexing 3. flexible rule language with negation and aggregation 4. fast incremental updates 5. explanation of inferences 6. monitoring rule evalaution process

Easy setup with Docker images in the Cloud, but also implementation on a local machine is very straightforward. Oxford Semantic provides excellent personal introduction sessions to bring you up to speed and start using the database. Datalog implementation is beneficial in overcoming OWL limitations (missing data, constraint checking). After some getting used to it, the data log rules are quite straightforward to apply. Also, if one gets stuck, the support by Oxford Semantics is very responsive (mostly within a business day). The help provided is beyond technical tool support as it also offers suggestions on how to solve specific problems with your rule sets or ontology structure. As far as I can say, the reasoning (processing new rule sets) is fast. Incremental reasoning (if new data is added) is also a great feature if you deal with massive data sets being updated regularly. Not less important: Oxford Semantics has a friendly team that makes it fun to interact with.