  In this technical paper we introduce the Tensor Network Theory (TNT) library
-- an open-source software project aimed at providing a platform for rapidly
developing robust, easy to use and highly optimised code for TNT calculations.
The objectives of this paper are (i) to give an overview of the structure of
TNT library, and (ii) to help scientists decide whether to use the TNT library
in their research. We show how to employ the TNT routines by giving examples of
ground-state and dynamical calculations of one-dimensional bosonic lattice
systems. We also discuss different options for gaining access to the software
available at http://www.tensornetworktheory.org.
