Both of the above are good. Others include:
Sesame - Java, covering RDF, SPARQL, OWL. Actively developed
Redland, Raptor Rasqal - C and Ruby, covers everything, is actively developing
ARC2 - PHP, RDF, SPARQL is no longer activated
You also have many supporting frameworks for things like ORDFM that build above:
Jenabean
Empire
Alibaba
RDFReactor
RDFBean
William Greenly
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