The GNOME canvas is a collaborative effort. The original version of the canvas was based on the Tk canvas widget. Federico Mena adapted it to the GTK+ object system and extended it with hierarchical groups. Raph Levien wrote the Libart engine and extended the original, GDK-only canvas to support it.
Many people have contributed with ideas and bug fixes to the canvas. The Gnumeric hackers provided excellent bug reports, and coped with our delays in fixing them. Tim Janik pointed out the most bizarre bugs in the antialiased canvas. Owen Taylor provided the scrolling backend for the canvas and was always knowledgeable and helpful with the intricacies of the X window system.
Red Hat, Inc. funded a large part of the development of the canvas, and provided a fun work environment and knowledgeable people. Helix Code, Inc. funded mainteinance work of the canvas.