Part I Harold Widom’s Life, Work, and Last Paper.- Biography of Harold Widom.- Domain Walls in the Heisenberg-Ising Spin-1/2 Chain.- Harold Widom’s Contributions to the Spectral Theory and Asymptotics of Toeplitz Operators and Matrices.- Visualizations of Two Functions Emerging in Connection with Toeplitz Determinants.- Part II Personal Notes.- A Remarkable Advisor, Mentor, and Friend.- My Encounters with Harold Widom.- Memories of Harold Widom.- Personal Reflection on Harold Widom.- Part III Invited Contributions.- Loops in SU (2) and Factorization, II.- Openness of Regular Regimes of Complex Random Matrix Models.- Focusing Nonlocal Nonlinear Schrödinger Equation with Asymmetric Boundary Conditions: Large-Time Behavior.- Algebras of Commuting Differential Operators for Kernels of Airy Type.- A Random Walk on the Rado Graph.- Widom Factors and Szeg˝o–Widom Asymptotics, a Review.- Some Recent Progress on the Stationary Measure for the Open KPZ Equation.- Probability of Two Large Gaps in the Bulk and at the Edge of the Spectrum of Random Matrices.- Multiplicative Properties of Infinite Block Toeplitz and Hankel Matrices.- Toeplitz and Related Operators on Polyanalytic Fock Spaces.- Strong Szeg˝o Theorem on a Jordan Curve.- Toeplitz Operators with Non-trivial Kernels and Non-dense Ranges on Weak Hardy Spaces.- Rényi Entropies of the Free Fermi Gas in Multi-Dimensional Space at High Temperature.- Spectral Asymptotics for Toeplitz Matrices Having Certain Piecewise Continuous Symbols.- Global and Local Scaling Limits for Linear Eigenvalue Statistics of Jacobi β-Ensembles.- On the Limit of Some Variable-Coefficient Toeplitz-Like Determinants.- On Diagonalizable Quantum Weighted Hankel Matrices.- On the Product Formula for Toeplitz and Related Operators.