parallel toolkit for 3D reconstructions in cryo-electron microscopy

 RELION (for REgularised LIkelihood OptimisatioN) is a stand-alone
 computer program for Maximum A Posteriori refinement of (multiple) 3D
 reconstructions or 2D class averages in cryo-electron microscopy.
 .
 RELION provides a GUI, several command-line tools in parallel (MPI) and serial
 versions as well as a C++ API.
 .
 relion-bin+gui provides the serial command-line tools and the graphical user
 interface.