If you have CPLEX available, the computation of optimal transports on grids for squared Euclidean cost can be accelerated considerably by linking against it. To do so, adapt the file src/Makevars according to the instructions given there. If you install CGAL (the Computational Geometry Algorithms Library) transport can solve semidiscrete optimal transport problems for (unsquared) Euclidean cost. Install CGAL from https://www.cgal.org/download.html and adapt the file src/Makevars according to the instructions given there. Then/otherwise installation is as usual for source packages.