Project documentation can be found here https://esa.github.io/pagmo_plugins_nonfree/
pagmo documentation can be found here https://esa.github.io/pagmo2/
WARNING: plugin compatible with worhp 1.14 and snopt < 7.7 (with the snopt7_c interface built by the github project snopt-interface, commit 76b166ecdf5c55a3289ce0f849d8d3d101954a22.). It will not work with worhp 1.13 or any other version, nor snopt 7.7 (headers were changed upstream).
If anyone needs us to develop plugins for those versions vote up the related issues.