HAL is an open archive where authors can deposit scholarly documents from all academic fields. It has a very good position in the international web repository ranking. HAL is run by the Centre pour la communication scientifique directe, a French computing centre, which is part of the French National Centre for Scientific Research, CNRS. Other French institutions, such as INRIA, have joined the system. While it is primarily directed towards French academics, participation is not restricted to them.
HAL seems to provide trade-free access to scientific articles. However, there are some trackers on the website which is why some blocks can be deduced: https://www.directory.trade-free.org/wp-content/uploads/2022/08/HAL-uBlock-Origin-scaled.jpg + https://www.directory.trade-free.org/wp-content/uploads/2022/08/HAL-trackers.jpg