The Horst graph library offers an easy to use,KISS graph library,without sleepless nights. We searched such a lib for our project Horst, but found no one that fits our performance,flexibility and simplicity needs.
Lodex-Linked Open Data Extraction Tool enables to extract large (millions of entities) ontology vocabularies out of unstructured data such as document text or social network messages. You can create own vocabularies easily for entity linking. It can run as a library or service.