As stated on the website at the time: "Along with books, The Online Books Page is also now listing major archives of serials (such as magazines, published journals, and newspapers) (...). Serials can be at least as important as books in library research. Serials are often the first places that new research and scholarship appear. They are sources for firsthand accounts of contemporary events and commentary. They are also often the first (and sometimes the only) place that quality literature appears. (For those who might still quibble about serials being listed on a 'books page', back issues of serials are often bound and reissued as hardbound 'books'.)" In 1999, after graduating from Carnegie Mellon with a Ph.D. in computer science, John Mark was hired as a digital library planner and researcher at the University of Pennsylvania Library. He also moved The Online Books Page there, kept it as clear and simple, and went on expanding it. The Online Books Page offered links to 12,000 books in 1999, 20,000 books in 2003 (including 4,000 books published by women), 25,000 books in 2006, 30,000 books in 2008 (including 7,000 books from Project Gutenberg) and 35,000 books in 2010. The books "have been authored, placed online, and hosted by a wide variety of individuals and groups throughout the world". The FAQ listed copyright information about most countries in the world, with links to further reading. 1993 > PDF, FROM PAST TO PRESENT [Summary] From California, Adobe launched PDF (Portable Document Format) in June 1993, along with Acrobat Reader (free, to read PDFs) and Adobe Acrobat (for a fee, to create PDFs). As stated on the website, PDF "lets you capture and view robust information from any application, on any computer system and share it with anyone around the world.” As the "veteran" format, PDF was perfected over the years as a global standard for distribution and viewing of information. Acrobat Reader was available in several languages, for various platforms (Windows, Mac, Linux, Palm OS, Pocket PC, Symbian OS, etc.), and for various devices (computer, PDA, smartphone). In May 2003, Acrobat Reader (5th version) merged with Acrobat eBook Reader (2nd version) to become Adobe Reader, starting with version 6, which could read both standard PDF files and secure PDF files of copyrighted books. *** From California, Adobe launched PDF (Portable Document Format) in June 1993, along with Acrobat Reader (free, to read PDFs) and Adobe Acrobat (for a fee, to make PDFs). As stated on the website, PDF "lets you capture and view robust information from any application, on any computer system and share it with anyone around the world. Individuals, businesses, and government agencies everywhere trust and rely on Adobe PDF to communicate their ideas and vision.”