Ert has been split into three repositories, libecl, libres, and ert, and now lives at Equinor's GitHub organization — https://github.com/equinor/libecl | https://github.com/equinor/libres | https://github.com/equinor/ert
The ert repository has been split in two independent repositories, and the development on the ert git repository has been discontinued.
https://github.com/Statoil/libecl : Project with main focus on reading and writing of ECLIPSE binary files.
https://github.com/Statoil/libres : Project with libraries and the main ERT application.