Some comments on the history, theory, and applicationsof symplectic reduction.- Homology of complete symbols and non-commutative geometry.- Cohomology of the Mumford quotient.- Poisson sigma models and symplectic groupoids.- Pseudo-differential operators and deformation quantization.- Singularities and Poisson geometry of certainrepresentation spaces.- Quantized reduction as a tensor product.- Analysis of geometric operator on open manifolds: a groupoid approach.- Smooth structures on stratified spaces.- Singular projective varieties and quantization.- Poisson structure and quantization of Chern-Simons theory.- Combinatorial quantization of Euclidean gravityin three dimensions.- The Yang—Mills measure and symplectic structureover spaces of connections.