An interface definition language (IDL) is a nontraditional language for describing interfaces between software components. IDL compilers generate “stubs” that provide separate communicating processes with the abstraction of local object invocation or procedure call. High-quality stub generation is essential for applications to benefit from componentbased designs, whether the components reside on a single computer or on multiple networked hosts. Typical IDL compilers, however, do little code optimization, incorrectly assuming that interprocess communication is always the primary bottleneck. More generally, typical IDL compilers are “rigid” and limited to supporting only a single IDL, a fixed mapping onto a target language, and a narrow range of data encodings and transport mechanisms. Flick, our new IDL compiler, is based on the insight that IDLs are true languages amenable to modern compilation techniques. Flick exploits concepts from traditional programming language compil...