Silicon Graphics
Haeberli was recruited by James H. Clark to join Silicon Graphics during the company's founding. Haeberli's early work included code, developed with David J. Brown and Mark Grossman, for SGI's first product – the Iris1000. Between 1983–1999, Haeberli continued at Silicon Graphics in Silicon Valley, California. He worked on the early MEX window system for Silicon Graphics workstations. He was also involved in non-photorealistic rendering (NPR) techniques in computer graphics, producing software to implement this approach. He devised the Silicon Graphics Image (SGI) format for graphics files. Later, he became an initial member of the research team at Silicon Graphics.