For mathematical background and applications, see
Version 1.7 of this package was accepted for publication in volume 5 of the journal The Journal of Software for Algebra and Geometry on 2013-09-18, in the article Computing free bases for projective modules. That version can be obtained from the journal or from the Macaulay2 source code repository, http://github.com/Macaulay2/M2/blob/master/M2/Macaulay2/packages/GraphicalModels.m2, commit number 8a3b2962b97153977eeaf6f92b5f48e246dd8e69.
This documentation describes version 1.7 of QuillenSuslin.
The source code from which this documentation is derived is in the file QuillenSuslin.m2.