In a move geared partly toward making publishers more comfortable with selling ebooks directly to libraries, Impelsys announced last week that its iPublishCentral software now enables publishers to set expiration terms for patron downloads of their titles, institution by institution. iPublishCentral 4.0 will also enable patrons to access ebooks from iPads, laptops, and desktop computers offline, regardless of the form of online patron authentication that is set up by their library.