The day when scientific articles are all freely available online seems close at hand, all of a sudden.

Harvard University announced yesterday that members of its faculty of Arts and Sciences will be required to put all their scientific articles in a free online repository maintained by the universityʼs library.

That comes on the heels of two other major announcements in the last month.

On 11 January the US National Institutes of Health said that all scientists who are funded by the agency ― which is practically every academic researcher in the US ― would be required to place “an electronic version of their final, peer-reviewed manuscripts upon acceptance for publication, to be made publicly available no later than 12 months after the official date of publication.”

The day before that, a similar policy set by the European Research Council set the mandatory date for scientists it funds at 6 months.

By requiring open access immediately after the article has been accepted for publication, Harvardʼs stance goes much further.

Open access to information has been gaining steam at universities for a while and some, such as the University of California, Berkeley, and the Massachusetts Institute of Technology, have been posting their lectures, course materials and exams online.

But this is the first time that an American university has introduced a mandatory rule of open access for research articles. And Harvard being the heavyweight that it is, other schools are sure to follow.

These policies are of course great, but donʼt address some lingering questions.

The most immediate one is about copyright.

Most journals own the copyright to the articles they publish and, because they invest significant time and money ― which I know full well from my days at Nature Medicine ― into the peer review process and on editorial processing of the article, expect to make a profit.

Some journals, but certainly not all, now allow authors to post their articles online, but typically only a version that hasnʼt yet been edited for clarity. So which version will be freely available online? Will multiple versions of articles create confusion?

In the case of my former employer Nature, for instance, scientists are free to release their unedited manuscripts online 6 months after publication. Can Harvard researchers still publish in the Nature brand of journals?

And what about those journals that donʼt allow even that? Can scientists use a waiver to publish in those journals? Will these developments force those for-profit journals to change their policies?