Authorities in numerical analysis and optimisation combine to write an important volume in the area.Michael Powell is one of the world's foremost figures in numerical analysis. This volume is derived from invited talks given at a meeting celebrating his 60th birthday and, reflecting Pow ell's own achievements, focuses on innovative work in optimization and in approximation theory. The individual papers have been written by leading authorities and together form a coherent volume that represents the state of the art in an important discipline within mathematics, with highly relevant applications throughout science and engineering.Michael Powell is one of the world's foremost figures in numerical analysis. This volume is derived from invited talks given at a meeting celebrating his 60th birthday and, reflecting Pow ell's own achievements, focuses on innovative work in optimization and in approximation theory. The individual papers have been written by leading authorities and together form a coherent volume that represents the state of the art in an important discipline within mathematics, with highly relevant applications throughout science and engineering.This volume is derived from invited talks given at a meeting celebrating Michael Powell's sixtieth birthday and focuses on innovative work in optimization and approximation theory. The individual papers, written by leading authorities in their subjects, are a mix of expository articles and surveys on new work. They have all been reviewed and edited to form a coherent volume that represents the state of the art in an important discipline within mathematics, with highly relevant applications throughout science and engineering.Preface; Submitted talks; 1. M. J. D. Powell's contributions to numerical mathematics M. D. Buhmann and R. Fletcher; 2. MJDP-BCS industrial liaison: applications to defence science I. Barrodale and C. Zala; 3. On the Meir/Sharma/Hall/Meyer analysis of the spline interpolation error C. de Boor; 4. l3(