Adobe Systems Incorporated, commonly known as Adobe, is an American multinational computer software company. Adobe has historically focused upon the creation of multimedia and creativity software products, with a more recent foray towards rich Internet application software development. It is best known for Photoshop, an image editing software, Acrobat Reader, the Portable Document Format (PDF), and Adobe Creative Suite, as well as its successor, Adobe Creative Cloud. Adobe was founded in December 1982 by John Warnock and Charles Geschke, who established the company after leaving Xerox PARC in order to develop and sell the PostScript page description language. In 1985, Apple Computer licensed PostScript for use in its LaserWriter printers, which helped spark the desktop publishing revolution.