Hepaxpert—a knowledge-based interpretive system for hepatitis A, B, and C serology test results—has now been rendered suitable for production by Medexter Healthcare. It is being routinely used at the Department of Laboratory Diagnosis, Franz Josef Hospital, Vienna, since 1998 onward. Technically, Hepaxpert is available as an Arden-Syntax-MLM medical knowledge package either with or without an Arden Syntax rule engine. It can be integrated into medical or laboratory information systems, used as a web-based medical decision support system with browser-based or direct server access, or be delivered as a stand-alone application or even as a simple rule package for customer-specific implementation.