One of the major early problems that biometrics faced was the lack of interoperability between different software applications and devices developed by different vendors. The BioAPI Specification has defined an open system standard application program interface (API) which allows software applications to communicate with a broad range of biometric technologies. This paper describes the design and implementation of an open source Java framework intended to provide single sign-on web authentication based on BioAPI-compliant biometric software or devices. The open-source principle makes this system a novel and practical development tool for testing and integrating biometric modules and devices from third parties. Key words: Biometrics, web authentication, BioAPI, open source