Coxeter is a computer program for the study of combinatorial aspects of Coxeter group theory, particularly those related to the Bruhat ordering and Kazhdan-Lusztig polynomials. The main capabilities of the program are the following : Reduced expression and normal form computations; Bruhat ordering; Ordinary Kazhdan-Lusztig polynomials; Kazhdan-Lusztig polynomials with unequal parameters; Inverse Kazhdan-Lusztig polynomials; Cells and W-graphs. Note: this port is specially crafted to be used with SageMath, with patches from Sage. See also: https://github.com/tscrim/coxeter