Bill Atkinson, an Apple Computer designer who created the software that enabled the transformative visual approach pioneered by the company’s Lisa and Macintosh computers, making the machines accessible to millions of users without specialized skills, died Thursday night at his home in Portola Valley, California, in the San Francisco Bay Area. He was 74.Atkinson programmed QuickDraw, a foundational software layer used for both the Lisa and Macintosh computers. Composed of a library of small programs, it made it possible to display shapes, text and images on the screen efficiently.The QuickDraw programs were embedded in the computers’ hardware, providing a distinctive graphical user interface that presented a simulated “desktop,” displaying icons of folders, files and application programs.Atkinson is credited with inventing many of the key aspects of graphical computing, such as “pull-down” menus and the “double-click” gesture, which allows users to open files, folders and applications by clicking a mouse button twice in succession.Before the Macintosh was introduced in January 1984, most personal computers were text-oriented; graphics were not yet an integrated function of the machines. And computer mice pointing devices were not widely available; software programs were instead controlled by typing arcane commands.The QuickDraw library had originally been designed for Apple’s Lisa computer, which was introduced in January 1983. Intended for business users, the Lisa predated many of the Macintosh’s easy-to-use features, but priced at $10,000 (almost $33,000 in today’s money), it was a commercial failure.Story continues below this adA year later, however, QuickDraw paved the way for the Macintosh graphical interface. It was based on an approach to computing that had been pioneered during the 1970s at Xerox’s Palo Alto Research Center by a group led by computer scientist Alan Kay. Kay was trying to create a computer system that he described as a Dynabook, a portable educational computer that would become a guiding light for Silicon Valley computer designers for decades.Xerox kept the project secret, but Dynabook nevertheless ultimately informed the design of the Lisa and the Macintosh. In an unusual agreement, Xerox gave Apple co-founder Steve Jobs and a small group of Apple engineers, including Atkinson, a private demonstration of Kay’s project in 1979.The group, however, was not permitted to examine the software code. As a result, the Apple engineers had to make assumptions about the Xerox technology, leading them to make fundamental technical advances and design new capabilities.In “Insanely Great,” a book about the development of the Macintosh, Steven Levy wrote of Atkinson, “He had set out to reinvent the wheel; actually he wound up inventing it.”Atkinson’s programming feats were renowned in Silicon Valley.Story continues below this ad“Looking at his code was like looking at the ceiling of the Sistine Chapel,” recalled Steve Perlman, who as a young Apple hardware engineer took advantage of Atkinson’s software to design the first color Macintosh. “His code was remarkable. It is what made the Macintosh possible.”In an early Apple commercial for the Macintosh, Atkinson described himself “as a cross between an artist and an inventor.”He was also the author of two of the most significant early programs written for the Macintosh. One of them, MacPaint, was a digital drawing program that came with the original Macintosh. It made it possible for a user to create and manipulate images on the screen, controlling everything down to the level of the individual display pixel.Ordinary users without specialized skills could now create drawings, illustrations and designs directly on a computer screen. The program introduced the concept of a “tool palette,” a set of clickable icons to select simulated paintbrushes, pens and pencils.Story continues below this adMacPaint had a significant impact in helping to transform computers from business and hobbyist systems into consumer products that could be marketed as tools to enable individual creativity.