He has developed application software, authoring tools, and software components for math and science education on the ESCOT (http://www.escot.org), WHIRL (http://www.projectwhirl.org), and Math Insight projects. He is currently developing tools to support undergraduate software design teams in the TRAILS project (http://www.trails-project.org). Prior to SRI International, he was a member of technical staff at Netscape Communications and a developer at the Institute for the Learning Sciences at Northwestern University.