I received my Ph.D. in computer science from the University of Copenhagen (DIKU) in 1996 on research in using formal rewriting systems to understand the operational semantics and memory management in functional programming languages. I continued academic research for four years, principally as an associate professor at Ecole Normale Supérieure (LIP) in Lyon, France, investigating and further developing results in higher-order rewriting and explicit substitution.
Since joining the IBM Thomas J. Watson Research Center in 2000, I have focused on making XML processing scalable even over diverse and distributed data sources, including large data collections and data not in XML, and even when running across multiple different runtime platforms. Specifically I have developed compiler generation techniques that permit systematic specification of how to apply advanced programming language and database query analysis techniques to the XML processing languages XSLT and XQuery.
To this end I dabble in foundational research on the use of transformation systems to specify directly executable specifications of such systems. Most recently this has lead me to implement the CRSX rewrite engine especially designed to permit using general higher order rewriting as an implementation language for compilers.