Open access is employed differently across different disciplines. Find information here about OA in the Humanities, Social Sciences and Sciences.
The list below provides a number of useless repositories that host Open Access publication in the Humanities and Social Sciences. It is by no means exhaustive, but should provide a good overview of some of the open resources available.
The Sciences have often led the way in the Open Access movement. This list is by no means exhaustive and is intended to provide a sense of the range of types of resources available.