In the GNU page for GSL: https://www.gnu.org/software/gsl/ the section for wrappers suggests PyrexGsl as a Pyrex wrapper. However, that package hasn't been updated since a long time (same for pyrex) and doesn't cover newer additions to GSL. It would be more appropriate to point towards its fork CythonGSL (https://github.com/twiecki/CythonGSL) , which works with cython (successor of pyrex).
