Open Science Directory. Search tool for open access journals and journals in special programs for developing countries. 

The Academic Journals publishes research articles in all areas of human study without financial restriction to readers using the open access model of publication. It covers research articles on medical sciences, social sciences, biological sciences, physical sciences, arts and education, legal sciences and other studies like peace and development studies.

Papers in Physics. This journal publishes original research in all areas of Physics and its interface with other subjects. 

GreenFILE. A freely accessible research database focusing on topics about the environment and related issues. 

PLoS. The Public Library of Science (PLoS) is a nonprofit organization of scientists and physicians committed to making the world’s scientific and medical research articles a freely available public resource.

Bioline International is a pioneer in the provision of open access to peer reviewed bioscience journals published in developing countries. These journals contain timely research on public health, international development, tropical medicine, food and nutritional security and biodiversity that would not otherwise be readily available to researchers in the developed world, or even within the country of publication. Bioline is not a publisher, but an aggregator that provides a free platform for journals who wish to participate in the global open access movement. 

BENTHAM OPEN publish over 230 peer-reviewed open access journals. These free-to-view online journals cover all major disciplines of science, technology, medicine and social sciences.