He received the PhD degree in computer science from The University of Tokyo in 1996. His PhD research was done at Xerox PARC in USA. Before moving Tokyo Institute of Technology, he has been working at University of Tokyo and University of Tsukuba. He has been also a short-term visiting professor at Ecole des Mines de Nantes in 1999 and Paris VI in 2004. He has been developing several software products including OpenC++, OpenJava, and Javassist, which have been distributed as open source software and widely used in both academia and industry.