Advanced programming language design in enterprise software: a lambda-calculus theorist wanders into a datacenter

Enterprise software systems automate the business processes of most nontrivial organizations in the world economy. These systems are immensely complex, and their function is critical to our living standards and everyday lives. Their design, implementation, and maintenance occupies many thousands of programmers and engineers, who work in what are aptly called the "COBOL dungeons"1 of the IT sector. These systems have persisted, growing by accretion -- some for decades; there are enterprise systems in existence today whose original and even subsequent authors are retired or deceased. Such extraordinarly old, multi-layered systems might appear to be the last place to apply avante-garde techniques, but in fact, they are extremely promising candidates, and for reasons directly connected to their history and structure.In this talk we take a tour of several deployed enterprise software systems, and demonstrate that the appropriate application of methods from functional programming can and does in fact yield dramatic performance improvements and thus commercial advan-tage in the design and implementation of enterprise software. This concrete application is an instance of a general plan for the application of advanced programming language design and analysis methods, to the problem of improving enterprise software. It is the thesis of this talk that to a great extent, it is in enterprise software that advanced PL techniques can find their most advantageous application. This talk literally breaks no new ground in PL research: every technique discussed is nearly two decades old, and our goal is to introduce PL researchers to what we feel is an ideal target for their work.