Abstract
The SOAP (Study of Open Access Publishing) project has analyzed the current supply and demand situation in the open access journal landscape. Starting from the Directory of Open Access Journals, several sources of data were considered, including journal websites and direct inquiries within the publishing industry to comprehensively map the present supply of online peer-reviewed OA journals. The demand for open access publishing is summarised, as assessed through a large-scale survey of researchers' opinions and attitudes. Some forty thousand answers were collected across disciplines and around the world, reflecting major support for the idea of open access, while highlighting drivers of and barriers to open access publishing.