Specialized computer algebra system GINV. The computer algebra system GINV (Gröbner INVolutive) is presented. It is designed for studying and solving systems of algebraic, differential, and difference equations of polynomial type by their completion to involution. The system is based on algorithms for constructing involutive Janet and Janet-like bases for polynomial ideals and modules, as well as reduced Gröbner bases, developed by the authors. GINV consists of a library of C++ programs, which is a module of the Python language. It is available at and is distributed under the terms of the GPL v2.