Open Access Week is global: learn to change the default to Open Access in order to redefine the impact of scholarship and research.
(Adapted from http://www.openaccessweek.org/profiles/blogs/welcome-to-open-access-week)
This guide was originally created by Boston College University Libraries and is licensed for use under a Creative Commons Attribution-ShareAlike 3.0 Unported License. 
"Open-access (OA) literature is digital, online, free of charge, and free of most copyright and licensing restrictions.
What makes it possible is the internet and the consent of the author or copyright-holder."
From Peter Suber's Very brief introduction to Open Access.