Hyper Articles en Ligne, generally shortened to HAL, is an open archive where authors can deposit scholarly documents from all academic fields. It was founded in 2000.
HAL is run by the Centre pour la communication scientifique directe a French computing center, 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 by no means restricted to them.
More information on the Wikipedia page [1]
The English language version of the website is [2].