  We present an extensively updated version of the purely ray-tracing 3D dust
radiation transfer code DART-Ray. The new version includes five major upgrades
: 1) a series of optimizations for the ray-angular density and the scattered
radiation source function; 2) the implementation of several data and task
parallelizations using hybrid MPI+OpenMP schemes; 3) the inclusion of dust
self-heating; 4) the ability to produce surface brightness maps for observers
within the models in HEALPix format; 5) the possibility to set the expected
numerical accuracy already at the start of the calculation. We tested the
updated code with benchmark models where the dust self-heating is not
negligible. Furthermore, we performed a study of the extent of the source
influence volumes, using galaxy models, which are critical in determining the
efficiency of the DART-Ray algorithm. The new code is publicly available,
documented for both users and developers, and accompanied by several programmes
to create input grids for different model geometries and to import the results
of N-body and SPH simulations. These programmes can be easily adapted to
different input geometries, and for different dust models or stellar emission
libraries.
