arXiv is an open access repository of scientific research open to users worldwide. It is a forum for scholarly communication moderated, informed and guided by scientists. Individual researchers can deposit their own content in arXiv free of charge. It provides open access to nearly two million papers in the fields of physics, mathematics, computer science, quantitative biology, statistics, electrical engineering, and economics.

It is funded by Cornell University, the Simmons Foundation and member institutions, which are libraries, laboratories, professional organizations and research institutions, foundations and other non-profit entities. CSIC has been a member of arXiv since 2010.

Since 1991, researchers have been able to share research with colleagues prior to publication thanks to arXiv. Speed and openness have become essential elements for the progress of research.

It is now 30 years since the birth of arXiv, an event to be celebrated by the entire scientific community.

Researchers prefer their progress to depend on doing more work or having a key idea, rather than having privileged access to essential materials. (Paul Ginsparg, founder of arXiv, 2011