Washington – The new public library on San Antonio's south side is missing something that once seemed unthinkable: books.

The south central Texas city's completely digital library, known as the BiblioTech, lets Bexar County readers check out up to five books at a time on their devices from home or wherever they are. Military personnel can even download a bestseller from Afghanistan.

No device? No problem.

Locals can check out tablets or e-readers for free. Or they can use the library's 48 iMac desktop computers. Children can take home the 200 Nook readers preloaded with 150 books aimed at their age group.

BiblioTech is the nation's first totally book-free public library. It just added a satellite branch in the jury room of the Bexar County Courthouse. The name plays off the word "biblioteca": Spanish for library.

In Washington, the downtown Martin Luther King Jr. Memorial Library cleared the stacks in one wing last June to open a vast, bookless "Digital Commons" — part computer lab, part design center and part reading lounge.

The bound book has held sway for 500 years, and doesn't look like it's going away anytime soon. But the digital age, which has crept into libraries through new technology, is slowly taking over.

A number of ambitious digital efforts are underway, focused on making cultural heritage books, manuscripts and books available online. The Digital Public Library of America and a Library of Congress-supported World Digital Library, which just reached 10,000 entries this past week, are making literary treasures, such as an early 16th-century Gospel manuscript from Ethiopia, more accessible.

"This project is of enormous benefit to students, teachers, scholars and lifelong learners," Librarian of Congress James Billington said.

At the MLK library, there's a giant touch screen used for teaching classes and a 3-D printer that on a recent afternoon was in the process of building a small basket. There's also a new book printer machine that will print and bind a book, small work spaces for people who need places for start-ups, a sound studio and a touch-screen table in the children's section for reading and playing. There's even a bank of express computers that visitors, no library card needed, can use for 15 minutes.

At North Carolina State University's new James B. Hunt Jr. Library in Raleigh, the 1.5 million books are stored underground, leaving space for research and study groups. Virtual stacks enable students to check out books from a robotic retrieval system that delivers them in five minutes or less.

"There are a lot of libraries that are shifting that way," said Barbara Stripling, the president of the American Library Association. "One of the biggest worries of libraries is equitable access."