Expository Articles.- Overdetermined Systems, Conformal Differential Geometry, and the BGG Complex.- Generalized Wilczynski Invariants for Non-Linear Ordinary Differential Equations.- Notes on Projective Differential Geometry.- Ambient Metric Construction of CR Invariant Differential Operators.- Fine Structure for Second Order Superintegrable Systems.- Differential Geometry of Submanifolds of Projective Space.- Pseudo-Groups, Moving Frames, and Differential Invariants.- Geometry of Linear Differential Systems Towards Contact Geometry of Second Order.- Research Article.- On Geometric Properties of Joint Invariants of Killing Tensors.- Hamiltonian Curve Flows in lie Groups G ? U(N) and Vector Nls, mKdV, Sine-Gordon Soliton Equations.- Conformal Killing Spinors and the Holonomy Problem in Lorentzian Geometry - A Survey of New Results -.- Projective-Type Differential Invariants for Curves and Their Associated Pdes of Kdv Type.- Algebraic Construction of the Quadratic First Integrals for a Special Class of Orthogonal Separable Systems.- Geometry of Non-Regular Separation.- Higher Symmetries of the Square of the Laplacian.- Metric Connections in Projective Differential Geometry.- Exterior Differential Systems with Symmetry.- Partially Invariant Solutions to Ideal Magnetohydrodynamics.- Invariant Prolongation and Detour Complexes.- Inhomogeneous Ambient Metrics.- Pfaffian Systems Of Frobenius Type And Solvability Of Generic Overdetermined Pde Systems.- Exact And Quasi - Exact Solvability of Second Order Superintegrable Quantum Systems.- A Remark On Unitary Conformal Holonomy.- Polynomial Associative Algebras for Quantum Superintegrable Systems with a Third Order Integral of Motion.- Separation of Variables for Systems of First-Order Partial Differential Equations and the Dirac Equation in Two-Dimensional Manifolds.- Differential Systems Associated with Tableaux over Lie Algebras.- Conformal Structures with Explicit Ambient Metrics and Conformal G 2 Holonomy.- Deformations of Quadratic Algebras, the Joseph Ideal for Classical Lie Algebras, and Special Tensors.- Analogues of the Dolbeault Complex and the Separation of Variables.