It is possible to read PDF documents such as Westinghouse user manuals using the Adobe Reader program produced by Adobe Systems. Many Web browsers also include PDF reader functionality that is either built into the browser itself or added through plug-in software.
Adobe Systems initially developed the Portable Document Reader format primarily for use in desktop publishing. The format was openly available but was owned and developed by Adobe until it was released as an open standard in 2008. This allowed Web browsers such as Firefox to develop integrated PDF readers for their applications, though many browsers still use plug-in readers developed by Adobe.