"Open Access" means free availability on the internet to academic or scientific literature (particularly peer-reviewed articles), permitting any users to read, download, copy, distribute, print, search, or link to the full texts.

There are three fudamental declarations (also know as the 3 B's – Budapest, Bethesda and Berlin)  related with open access:

Budapest Open Access Initiative
On December of 2001 was held a meeting in Budapest promoted by the Open Society Institute (OSI) to discuss the question of the access to scientific literature. The result was the Budapest Open Access Initiative (BOAI), a document and an initiative that is, at the same time, a principle declaration, a strategic definition and a commitment statement. For this it's one of the most important documents of the Open Access Movement.

Bethesda Statement on Open Access Publishing
On the 11th April 2003 several personalities (scientists, publishers, librarians, etc.) with interests in biomedical information met at the head office of Howard Hughes Medical Institute with the purpose of stimulating the discussion on the way to accomplish, as soon as possible, the objective of reassure open access to scientific literature. The declaration has a definition of Open Access, as well as conclusions and recommendations of working groups of I&D organizations and financing institutions, libraries and publishers, scientific societies and researchers.

Berlin Declaration on Open Access to Knowledge in the Sciences and Humanities
This declaration was subscribed on the 22th october 2003 by various representatives of important European scientific institutions, among which Max-Plank Society (Germany) and National Centre of Scientific Research (France), supporting Open Access and the deposit in open access archives and restating that they will encourage their researchers and grantees to deposit their work in at least one repository.

The last year accentuates the confirmation of the Open Access movement and its entry on the social and political agenda, far beyond the frontiers of the scientific world, as it is shown by several documents and decisions undertaken by scientific societies and governmental organizations. In this matter we can point numerous documents:

Declaration of Principles and Plan of Action of the World Summit on the Information Society (WSIS)
Document approved in Geneva, on December 2003, during the world summit, explicitly supporting open access to scientific information. In the action plan it's recommended the encouragement of “initiatives to facilitate the access, including the open access economically viable to journals and books of open access and to open archives of scientific information”.

Declaration on Access to Research Data from Public Funding/OCDE
On the 30th January 2004, in Paris, the ministers of Science and Technology of 34 states members of OCDE made public a declaration recognising that open access maximizes the public value invested in science and technology and encouraging the governments to search regulations and policies promoting the international interchange of the results of the scientific investigation in a free way.

Scientific Publications: Free for all?
On the 20th July 2004, the House of Commons Science and Technology Committee presented a report on the prices and access of journals, that recommends to all universities in United Kingdom the creation of institutional repositories where their intellectual output can be deposited and freely available online for consultation without charges.

Scottish Declaration of Open Access
Scottish Declaration of Open Access Open Access Declaration created by the Scottish Science Information Strategy Working Group on the 11th of October 2004.