Klaus Darilion works for enum.at and nic.at, knowing Kamailio (OpenSER) and SER projects from the beginning, being a major developer, an active member on the mailing lists and an advocate of the project at various VoIP events.
He is doctor in computer science from Technical University Vienna, involved in ENUM and security of VoIP/SIP, author/contributor to other open source applications (e.g., QjSimple SIP phone) and papers related to these domains:
http://www.ipcom.at/index.php?id=565