The Original Creators of GIMP at UC Berkeley

The GNU Image Manipulation Program, widely known as GIMP, was originally created in 1995 by University of California, Berkeley students Spencer Kimball and Peter Mattis. Developed as a semester-long class project, the software was designed to provide a free, open-source alternative to proprietary image editing tools like Adobe Photoshop. This article explores the background of Kimball and Mattis, the circumstances surrounding GIMP’s inception at UC Berkeley, and its subsequent rise as a cornerstone of open-source software.

Spencer Kimball and Peter Mattis

Spencer Kimball and Peter Mattis were undergraduate students and members of the eXperimental Computing Facility (XCF), a student computer group at UC Berkeley. In 1995, while taking a computer science course, they set out to build a general-purpose image manipulation tool for Unix-like operating systems.

At the time, the software was named the "General Image Manipulation Program." Kimball and Mattis first announced the software to the public on the Usenet group comp.os.linux.development.apps on November 21, 1995, releasing version 0.54.

The Technological Impact

Developing GIMP required creating several underlying technologies that went on to have an enormous influence on the open-source ecosystem:

  • GTK (GIMP Toolkit): Kimball and Mattis originally built GIMP using Motif, a commercial widget toolkit. Frustrated by its limitations and proprietary licensing, they wrote their own toolkit, known as the GIMP Toolkit (GTK). GTK later evolved into GTK+, which eventually became the foundation for the GNOME desktop environment.
  • GDK and GLib: To support GTK, they separated the low-level graphics and non-UI data structure handling into the GIMP Drawing Kit (GDK) and GLib, both of which remain widely used today.

Transition to the GNU Project

Kimball and Mattis maintained the software through early releases, including version 0.99 in 1997. Following their graduation from UC Berkeley, they stepped away from active development to pursue other professional opportunities, eventually co-founding Cockroach Labs together years later.

Before departing, they agreed to rename the project to the "GNU Image Manipulation Program" upon Richard Stallman's request, officially making it part of the GNU Project in 1997. A global community of volunteer developers then assumed control of the codebase, ensuring the continuation and evolution of the program Kimball and Mattis created as university students.