All Documentation, binaries and original source code are available at www.openmesh.org
The main git repository is available at:
https://www.graphics.rwth-aachen.de:9000/OpenMesh/OpenMesh.git
The gitlab site can be found here:
https://www.graphics.rwth-aachen.de:9000/OpenMesh/OpenMesh
Unpack the tar-ball to a suitable place.
A detailed build manual for Mac/Windows/Linux is in the Documentation
located at Doc/html/index.html
The latest Documentation can be found at:
https://www.openmesh.org/media/Documentations/OpenMesh-Doc-Latest
Documentation for previous versions is available on our website as well.