From the SCOAP3 Blog:
The SCOAP3 initiative has converted to Open Access the majority of the literature in High-Energy Physics through a partnership of libraries, publishers, funding agencies and the research community in 35 countries.
About 400 new articles appear monthly on the publishers platform and on the SCOAP3 repository under a CC-BY license. PDF, PDF/A and XML formats are available on the SCOAP3 repository, together with full metadata under a CC0 waiver.
All “gold” Open Access articles published under the SCOAP3 initiative and their metadata are now exposed leveraging the Open Archive Initiative Protocol for Metadata Harvesting (OAI-PMH). As the de-facto standard technically underpinning the Open Access movements, OAI-PMH feeds allow the worldwide repository and library community to exchange information and enrich their services. The SCOAP3 repository handler is available at http://repo.scoap3.org/oai2d. Additional information, help and examples are available on the SCOAP3 website.
A community-driven development plan is publicly available.