LOC is a program, or rather a family of programs, aimed at the radiative transfer modelling of molecular lines. These will be made public… in near future. The main novelty is in the use of OpenCL libraries for the parallelisation of the computations so that they can be run both on multi-core CPUs and GPUs. Thus, the basic concept is the same as in the case of SOC, the radiative transfer code for calculations of dust emission and scattering.
At this moment there exist versions of LOC for 1D and regular Cartesian 3D grids. In addition to “normal” molecular line modelling, one can model spectra with hyperfine structure either by assuming local thermodynamic equilibrium between the components or by doing the full calculation, including the effects of line overlap. One of the next steps is to implement LOC for hierarchical grids.