From a Company Announcement:
McGraw-Hill Professional today announced that it is offering an enhanced purchasing program for its McGraw-Hill eBook Library.
This new purchasing alternative – perpetual access – is designed to give libraries more flexibility in acquiring McGraw-Hill Professional’s digital content to meet the growing demands from their patrons for eBooks.
“In a fast-changing environment, McGraw-Hill Professional continues to provide new ways to deliver our content and respond to our customers’ needs,” said Philip Ruppel , president of McGraw-Hill Education International and Professional. “Our enhanced perpetual access program is another way to ensure that libraries around the world have all of the options they need to build eBook collections to best serve their patrons.”
Read the Complete Announcement
The McGraw-Hill eLibrary launched in May 2011.