Publish in Open Access is synonym to make its publication freely accessible to everyone as defined by Peter Suber (Open Access, 2012. MIT Press):
Publish in an open repository (Green Open Access)
A repository can be institutional or thematic. At EPFL, the institutional repository is Infoscience. Numerous disciplinary repositories exist according to disciplines. Deposit its publication in a repository ensures a maximal visibility to its research outputs.
The deposit of a manuscript can be made before submission (preprint) or at the moment of the publication. After an embargo period from 6 months to 2 years set up by publishers, it is possible to archive the version post-revision of the manuscript (postprint) and sometimes the final version (PDF publisher). The conditions of Green Open Access deposit vary from publisher to publisher.
Publish in an Open Access journal (Pure Gold Open Access)
To finance the publication in Gold Open Access, the author has to pay fees (APC – Article Publishing Charge ou BPC – Book Publishing Charge). In this case, a financial support is offered by the Library.
Predatory publishers contact researchers (fishing by e-mail and phone) to offer them to publish in their journals. Their insistence encourages the utmost caution. These publishers are motivated by the gain. In case of doubt, the Library can help you to check the quality of a publisher or a journal.
Publish in a hybrid journal (Hybrid Open Access)
A hybrid journal is a subscription-based journal that offers an Open Access option making some of the articles freely accessible.
After acceptance of the manuscript, the publisher gives the option to the author to publish the article in Open Access, against the payment of an APC (Article Publishing Charge).
In the case of a publication in a hybrid journal, the EPFL Library does not offer a refund: since the Library already finances subscription costs for closed-access journals, the payment of APCs would represent a double dipping.