Another route to open access is the "green road": Authors self-archiving copies of their articles in open online repositories.
Authors may archive their preprints without a publisher's permission, and a majority of journals already permit authors to archive their post-prints (check SHERPA/RoMEO for policies of individual journals).
Pre-prints = the manuscript version of the paper before peer review.
Post-prints = the manuscript version of the paper after peer-review, with revisions having been made.
(These are SHERPA/RoMEO's definitions. Be aware that the definitions for these terms vary by discipline!)
Google Scholar indexes most institutional or subject repositories - allowing other researchers to easily locate this open access version of your article!
PeerJ PrePrints - a preprint repository for the life sciences: submit a draft that has not yet been peer reviewed for formal publication (in this way you can establish precedence, solicit feedback, and work on revisions before a formal submission).
arXiv.org - is a preprint repository in the fields of physics, mathematics, non-linear science, computer science, quantitative biology, quantitative finance and statistics.
SocArXiv - a preprint repository in the social sciences.
AgriXiv - a preprint repository in agriculture. Established Feb 2017.
Humanities Commons (CORE) - CORE is a full-text, interdisciplinary, non-profit social repository designed to increase the impact of work in the Humanities.
Cogprints - an archive of documents in the fields of psychology, neuroscience, linguistics, computer science, philosophy, and biology.
Computing Research Repository (CoRR) - is a computer science repository.
E-LIS - hosts e-prints in library and information science.
For those without access to an institutional or discipline repository... there are now some open repositories online that anyone in any disicipline can deposit their work in:
"The purpose of OpenDepot.org is to ensure that all academics worldwide can share in the benefits of making their research output Open Access. For those whose universities and organisations have an online repository, OpenDepot.org makes them easy to find. For those without a local repository, including unaffilitiated researchers, the OpenDepot is a place of deposit, available for others to harvest."
Zenodo is a "...service that enables researchers, scientists, EU projects and institutions to share and showcase multidisciplinary research results (data and publications) that are not part of the existing institutional or subject-based repositories of the research communities."
If the library doesn't subscribe to a journal you need then you can request through Inter-Library Loan or... try the Open Access Button!
This tool can get you instant, legal access to research - and request research that isn't available.
The OA Button searches across repositories for legally posted author's versions of articles. If an author has not posted such a version then OA Button reaches out to them to do so!
SHARE is a higher education initiative whose mission is to maximize research impact by making a comprehensive inventory of research widely discoverable, accessible, and reusable. To fulfill this mission SHARE is creating an openly available data set about research activities across their life cycle.
OAIster - is a union catalog of millions of records representing open access resources that was built by harvesting from open access collections worldwide using the Open Archives Initiative Protocol for Metadata Harvesting (OAI-PMH). Use OAIster to search across repositories.
BASE - The Bielefeld Academic Search Engine indexes academic open access web resources using the OAI-PMH (as above).
OpenAIRE - search across the open access contents of European repositories.
CORE (COnnecting REpositories) - aggregates repository content from all over the world.
OpenDOAR - search across the contents of repositories listed in this directory.
An institutional repository (IR) is a digital collection of an organization’s intellectual output. IRs centralize, preserve, and make accessible the knowledge generated by academic institutions benefiting both the institution and its scholars by raising the institutional profile while also bringing broader dissemination, increased use, and enhanced professional visibility of scholarly research.
eCommons - Institutional repository of the University of Saskatchewan. Currently the eCommons houses only theses and librarian research publications. Librarians and archivists at the UofS voted in favour of an Open Access Commitment in January 2010.
Canadian Institutional Respositories - A list maintained by the Canadian Association of Research Libraries (CARL).