...each Faculty member hereby grants to The Trustees of Princeton University a nonexclusive, irrevocable, worldwide license to exercise any and all copyrights in his or her scholarly articles published in any medium, whether now known or later invented, provided the articles are not sold by the University for a profit, and to authorize others to do the same.... The University hereby authorizes each member of the faculty to exercise any and all copyrights in his or her scholarly articles that are subject to the terms and conditions of the grant set forth above.
The legalese is making my head spin, but I think they are saying that the university gets full access to all faculty publications, and that the university is granting all faculty full access to their own publications. As a programmer, I yearn to write it in a more simple way, and probably to drop the "for a profit" part. Still, the spirit is there. Anything published by a Princeton faculty member will not be hidden exclusively behind a paywall.
Hat tip to Andrew Appel, who emphasizes that this policy is compatible with ACM's paywall:
Most publishers in Computer Science (ACM, IEEE, Springer, Cambridge, Usenix, etc.) already have standard contracts that are compatible with open access. Open access doesn't prevent these publishers from having a pay wall, it allows other means of finding the same information.
This is true, but I find it too gentle on ACM. The ACM is supposed to be the preeminent association of computer-science researchers in the United States. They would serve their members, not to mention science, if they made the articles open access. Charge the authors, not the readers.