Andrei A. Agrachev Born in Moscow, Russia. Graduated: Moscow State Univ., Applied Math. Dept., 1974. Ph.D.: Moscow State Univ., 1977. Doctor of Sciences (habilitation): Steklov Inst. for Mathematics, Moscow, 1989. Invited speaker at the International Congress of Mathematicians ICM-94 in Zurich. Over 90 research papers on Control Theory, Optimization, Geometry (featured review of Amer. Math. Soc., 2002). Professional Activity: Inst. for Scientific Information, Russian Academy of Sciences, Moscow, 1977-1992; Moscow State Univ., 1989-1997; Steklov Inst. for Mathematics, Moscow, 1992-present; International School for Advanced Studies (SISSA-ISAS), Trieste, 2000-present. Current positions: Professor of SISSA-ISAS, Trieste, Italy and Leading Researcher of the Steklov Ins. for Math., Moscow, Russia Yuri L. Sachkov Born in Dniepropetrovsk, Ukraine. Graduated: Moscow State Univ., Math. Dept., 1986. Ph.D.: Moscow State Univ., 1992. Over 20 research papers on Control Theory. Professional Activity: Program Systems Institute, Russian Academy of Sciences, Pereslavl-Zalessky, 1989-present; University of Pereslavl, 1993-present. Steklov Inst. for Mathematics, Moscow, 1998-1999; International School for Advanced Studies (SISSA-ISAS), Trieste, 1999-2001. Current positions: Senior researcher of Program Systems Institute, Pereslavl-Zalessky, Russia; Associate professor of University of Pereslavl, Russia.