According to the Study of Open Access Publishing (SOAP) project, about 33% of open access journals charge a fee. 59% of those fees are paid by funders (such as the NIH) and 24% are paid by universities through other grants
Library Support for Open Access Journals
The Penn Libraries also support the publishing of open access journals.
BioMedCentral - Penn Libraries pays an institutional membership which entitles Penn authors to a discount in their article processing charges. The submitting author must be faculty, student or staff of the University of Pennsylvania. Generally, visiting students and scholars are not eligible for support. Submitting author must use University of Pennsylvania as their author affiliation, and provide their University of Pennsylvania email address.
Penn Libraries has an Institutional Fellowship with BMJ Case Reports that ensures authors will not have to pay individual fellowship fees. Additionally, all faculty, staff and students at the University of Pennsylvania will be able to submit as many cases as they like as well as access to and reuse of all the published material.
PeerJ and PeerJ Computer Science -- Penn Libraries have an institutional plan with the PeerJ journals. PeerJ is a peer review open-acess publisher. It publishes articles on biology, medicine, general science, and all aspects of computer science. The libraires support a lifetime membership at the Basic level (basic level provides one article per year) for Penn faculty who have been accepted for publication with PeerJ.
ArXiv - Penn Libraries belongs to ArXiv, a repository well over 1,000,000 e-prints in Physics, Mathematics, Computer Science, Quantitative Biology, Quantitative Finance and Statistics
Browse journals and books published under a Creative Commons license and without an embargo. The publications can be read for free online and downloaded; paper copies may also be purchased at a reasonable cost.
ScholarlyCommons is Penn's institutional repository; it houses research done by the Penn community.