Adobe Portable Document Format (PDF) allows documents created through word processing to be made available on the web. PDF makes it possible for the fonts, format, and pagination to remain consistent when viewed from different devices (desktop computers, tablets, and mobile phones), with different operating systems such as Windows, Macintosh, and Unix and different Web browsers such as Internet Explorer, Firefox, and Chrome. Acrobat Reader can be downloaded for free, thus providing everyone with access to the document. The Association for Research Libraries (ARL) has set standards for archiving digital materials in PDF, so archiving is better ensured. Finally, PDF is the text-based format accepted by ProQuest for publishing dissertations.