Jef created the Macintosh computer as employee number 31 at Apple in the early 1980s, revolutionizing computer interface design.

Jef invented "click and drag" and many other methods now taken for granted by computer users.

He named the Macintosh project after his favorite variety of apple, the McIntosh, modifying the spelling for copyright purposes.

Jef died peacefully at home in California on February 26th, 2005 surrounded by his family and loved ones.

He had recently been diagnosed with pancreatic cancer.