EPW is licensed under a [GNU General Public License]
EPW is part of the [Quantum Espresso] software package.
The EPW software is only tested and intened to run on Linux (Mac OS might work but not tested).
Download the latest version of [Quantum-ESPRESSO].
Unpack and configure Quantum-ESPRESSO
tar -xvf espresso-5.4.0.tar.gz && cd espresso-5.4.0 && ./configure
make -j 4 pwall make -j 4 ph make -j 4 epw