  This paper is the documentation for a numerical code for quantum transport
called KNIT. The KNIT library implements a generalization of the well known
recursive Green function technique for a large class of multi-terminal
mesoscopic systems with arbitrary geometries, topology and dimension. The
systems are described by tight-biding Hamiltonians (with arbitrary internal
degree of freedom like spin, electron/hole grading, orbitals...) and the
calculation done within the non equilibrium Green function formalism
(equivalent to the Landauer-Buttiker Scattering approach). KNIT can (and has)
been applied to many different physical systems including quantum Hall effect,
topological insulators, graphene ribbons, hybrid superconducting systems and
ferromagnetic multilayers. KNIT main functionality is written in C++ and
wrapped into Python, providing a simple and flexible interface for the user.
Usual "input files" of numerical codes are replaced by small python scripts
where the user builds the system and then computes whatever observable
(conductance, noise, local density of states...) is needed. KNIT code can be
obtained freely at the following url:
http://inac.cea.fr/Pisp/xavier.waintal/KNIT.php
