Prior to that, he worked on debugger, profiler, and correctness tools for High Performance Computing (HPC) developers. Before HPC, he was in the Visual Studio and Microsoft Research groups where he worked on Microsoft's next-generation of compilers, JITs, and static analysis tools. Before Microsoft, he was at Sun Microsystems where he ran the code generation/optimization group for SPARC. He is a big proponent of open-source tools and technologies.