The Java programming environment is increasingly being used to build large-scale multi-language applications. Whether these applications combine Java with other languages for legacy reasons, to address performance concerns, or to add Java functionality to preexisting server environments, they require correct and efficient native interfaces. This paper examines current native interface implementations, presents performance results, and discusses performance improvements in our IRIX Java Virtual Machine and Just-In-Time Compiler that have sped up native interfacing by significant factors over previous releases.