Open Access is the free, immediate, online availability of research articles coupled with the rights to use these articles fully in the digital environment. Open Access ensures that anyone can access and use these results—to turn ideas into industries and breakthroughs into better lives (SPARC).
Publishers participating in open access may utilize one of the following models:
Gratis vs. Libre
Note: While 'free' implies that the information does not cost anything to access, remember that OA publishing still often involves a cost to the author to publish the work.
Directories of open access policies for journals and research funders open access requirements: