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. It is written in C++, and should run on the main types of workstation under linux or unix. The current version is now version 3.0, which is now available for beta testing. 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.