Implementation
reports for the RDFCore Working Group and Implementation reports for Web
Ontology Working Group are being prepared in preparation for W3C Proposed
Recommendation status
A large number of open source tools and toolkits have been developed
(Parsers, Reasoners, APIs, etc.)
In various languages (Java, Lisp, Python, PHP, Perl, C, C#, etc.)
Personal favorites I use on a weekly (daily) basis - Jena2 (java) and RDFlib (python)